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Outline
Categoryvt
DNA profiling (also called DNA fingerprinting) is the process of determining an individual's DNA characteristics, which are as unique as fingerprints. DNA analysis intended to identify a species, rather than an individual, is called DNA barcoding.
DNA profiling is a forensic technique in criminal investigations, comparing criminal suspects' profiles to DNA evidence so as to assess the likelihood of their involvement in the crime.[1] It is also used in parentage testing,[2] to establish immigration eligibility,[3] and in genealogical and medical research. DNA profiling has also been used in the study of animal and plant populations in the fields of zoology, botany, and agriculture.[4]
Background
The process of DNA profiling was developed in the United Kingdom in 1984[5] by geneticist Sir Alec Jeffreys[6][7][8][9] while working in the Department of Genetics at the University of Leicester.[10]
The process, developed by Jeffreys in conjunction with Peter Gill and Dave Werrett of the Forensic Science Service (FSS), was first used forensically in the solving of the murder of two teenagers who had been raped and murdered in Narborough, Leicestershire in 1983 and 1986. In the murder inquiry, led by Detective David Baker, the DNA contained within blood samples obtained voluntarily from around 5,000 local men who willingly assisted Leicestershire Constabulary with the investigation, resulted in the exoneration of Richard Buckland, an initial suspect who had confessed to one of the crimes, and the subsequent conviction of Colin Pitchfork on January 2, 1988. Pitchfork, a local bakery employee, had coerced his coworker Ian Kelly to stand in for him when providing a blood sample—Kelly then used a forged passport to impersonate Pitchfork. Another coworker reported the deception to the police. Pitchfork was arrested, and his blood was sent to Jeffrey's lab for processing and profile development. Pitchfork's profile matched that of DNA left by the murderer which confirmed Pitchfork's presence at both crime scenes; he pleaded guilty to both murders.[11]
Although 99.9% of human DNA sequences are the same in every person, enough of the DNA is different that it is possible to distinguish one individual from another, unless they are monozygotic (identical) twins.[12] DNA profiling uses repetitive sequences that are highly variable,[12] called variable number tandem repeats (VNTRs), in particular short tandem repeats (STRs), also known as microsatellites, and minisatellites. VNTR loci are similar between closely related individuals, but are so variable that unrelated individuals are unlikely to have the same VNTRs.
DNA profiling processes

The process begins with a sample of an individual's DNA (typically called a "reference sample"). Reference samples are usually collected through a buccal swab. When this is unavailable (for example, when a court order is needed but unobtainable) other methods may be needed to collect a sample of blood, saliva, semen, vaginal lubrication, or other fluid or tissue from personal use items (for example, a toothbrush, razor) or from stored samples (for example, banked sperm or biopsy tissue). Samples obtained from blood relatives can indicate an individual's profile, as could previous profiled human remains.  A reference sample is then analyzed to create the individual's DNA profile using one of the techniques discussed below.  The DNA profile is then compared against another sample to determine whether there is a genetic match.
DNA Extraction
When a sample such as blood or saliva is obtained, the DNA is only a small part of what is present in the sample. Before the DNA can be analyzed, it must be extracted from the cells and purified. There are many ways this can be accomplished, but all methods follow the same basic procedure. The cell and nuclear membranes need to be broken up to allow the DNA to be free in solution. Once the DNA is free, it can be separated from all other cellular components. After the DNA has been separated in solution, the remaining cellular debris can then be removed from the solution and discarded, leaving only DNA.[13] The most common methods of DNA extraction include organic extraction (also called phenol chloroform extraction), Chelex extraction, and solid phase extraction. Differential extraction is a modified version of extraction in which DNA from two different types of cells can be separated from each other before being purified from the solution. Each method of extraction works well in the laboratory, but analysts typically selects their preferred method based on factors such as the cost, the time involved, the quantity of DNA yielded, and the quality of DNA yielded.[14] After the DNA is extracted from the sample, it can be analyzed, whether it be RFLP analysis or quantification and PCR analysis.
RFLP analysis

The first methods for finding out genetics used for DNA profiling involved RFLP analysis. DNA is collected from cells and cut into small pieces using a restriction enzyme (a restriction digest). This generates DNA fragments of differing sizes as a consequence of variations between DNA sequences of different individuals. The fragments are then separated on the basis of size using gel electrophoresis.
The separated fragments are then transferred to a nitrocellulose or nylon filter; this procedure is called a Southern blot. The DNA fragments within the blot are permanently fixed to the filter, and the DNA strands are denatured. Radiolabeled probe molecules are then added that are complementary to sequences in the genome that contain repeat sequences. These repeat sequences tend to vary in length among different individuals and are called variable number tandem repeat sequences or VNTRs. The probe molecules hybridize to DNA fragments containing the repeat sequences and excess probe molecules are washed away. The blot is then exposed to an X-ray film. Fragments of DNA that have bound to the probe molecules appear as fluoresent bands on the film.
The Southern blot technique requires large amounts of non-degraded sample DNA. Also, Karl Brown's original technique looked at many minisatellite loci at the same time, increasing the observed variability, but making it hard to discern individual alleles (and thereby precluding paternity testing). These early techniques have been supplanted by PCR-based assays.
Polymerase chain reaction (PCR) analysis

Developed by Kary Mullis in 1983, a process was reported by which specific portions of the sample DNA can be amplified almost indefinitely (Saiki et al. 1985, 1985) The process,  polymerase chain reaction (PCR), mimics the biological process of DNA replication, but confines it to specific DNA sequences of interest. With the invention of the PCR technique, DNA profiling took huge strides forward in both discriminating power and the ability to recover information from very small (or degraded) starting samples.
PCR greatly amplifies the amounts of a specific region of DNA. In the PCR process, the DNA sample is denatured into the separate individual polynucleotide strands through heating. Two oligonucleotide DNA primers are used to hybridize to two corresponding nearby sites on opposite DNA strands in such a fashion that the normal enzymatic extension of the active terminal of each primer (that is, the 3’ end) leads toward the other primer. PCR uses replication enzymes that are tolerant of high temperatures, such as the thermostable Taq polymerase. In this fashion, two new copies of the sequence of interest are generated. Repeated denaturation, hybridization, and extension in this fashion produce an exponentially growing number of copies of the DNA of interest. Instruments that perform thermal cycling are readily available from commercial sources. This process can produce a million-fold or greater amplification of the desired region in 2 hours or less.
Early assays such as the HLA-DQ alpha reverse dot blot strips grew to be very popular due to their ease of use, and the speed with which a result could be obtained. However, they were not as discriminating as RFLP analysis. It was also difficult to determine a DNA profile for mixed samples, such as a vaginal swab from a sexual assault victim.
However, the PCR method was readily adaptable for analyzing VNTR, in particular STR loci. In recent years, research in human DNA quantitation has focused on new "real-time" quantitative PCR (qPCR) techniques. Quantitative PCR methods enable automated, precise, and high-throughput measurements. Inter-laboratory studies have demonstrated the importance of human DNA quantitation on achieving reliable interpretation of STR typing and obtaining consistent results across laboratories.
STR analysis

The system of DNA profiling used today is based on Polymerase chain reaction (PCR) and uses simple sequences[15] or short tandem repeats (STR). This method uses highly polymorphic regions that have short repeated sequences of DNA (the most common is 4 bases repeated, but there are other lengths in use, including 3 and 5 bases). Because unrelated people almost certainly have different numbers of repeat units, STRs can be used to discriminate between unrelated individuals. These STR loci (locations on a chromosome) are targeted with sequence-specific primers and amplified using PCR. The DNA fragments that result are then separated and detected using electrophoresis. There are two common methods of separation and detection, capillary electrophoresis (CE) and gel electrophoresis.
Each STR is polymorphic, but the number of alleles is very small. Typically each STR allele will be shared by around 5 - 20% of individuals. The power of STR analysis comes from looking at multiple STR loci simultaneously. The pattern of alleles can identify an individual quite accurately. Thus STR analysis provides an excellent identification tool. The more STR regions that are tested in an individual the more discriminating the test becomes.
From country to country, different STR-based DNA-profiling systems are in use. In North America, systems that amplify the CODIS 20[16] core loci are almost universal, whereas in the United Kingdom the DNA-17 17 loci system (which is compatible with The National DNA Database) is in use, and Australia uses 18 core markers.[17] Whichever system is used, many of the STR regions used are the same. These DNA-profiling systems are based on multiplex reactions, whereby many STR regions will be tested at the same time.
The true power of STR analysis is in its statistical power of discrimination. Because the 20 loci that are currently used for discrimination in CODIS are independently assorted (having a certain number of repeats at one locus does not change the likelihood of having any number of repeats at any other locus), the product rule for probabilities can be applied. This means that, if someone has the DNA type of ABC, where the three loci were independent, we can say that the probability of having that DNA type is the probability of having type A times the probability of having type B times the probability of having type C. This has resulted in the ability to generate match probabilities of 1 in a quintillion (1x1018) or more. However, DNA database searches showed much more frequent than expected false DNA profile matches.[18] Moreover, since there are about 12 million monozygotic twins on Earth, the theoretical probability is not accurate.
In practice, the risk of contaminated-matching is much greater than matching a distant relative, such as contamination of a sample from nearby objects, or from left-over cells transferred from a prior test. The risk is greater for matching the most common person in the samples: Everything collected from, or in contact with, a victim is a major source of contamination for any other samples brought into a lab. For that reason, multiple control-samples are typically tested in order to ensure that they stayed clean, when prepared during the same period as the actual test samples. Unexpected matches (or variations) in several control-samples indicates a high probability of contamination for the actual test samples. In a relationship test, the full DNA profiles should differ (except for twins), to prove that a person was not actually matched as being related to their own DNA in another sample.
AmpFLP

Another technique, AmpFLP, or amplified fragment length polymorphism was also put into practice during the early 1990s. This technique was also faster than RFLP analysis and used PCR to amplify DNA samples. It relied on variable number tandem repeat (VNTR) polymorphisms to distinguish various alleles, which were separated on a polyacrylamide gel using an allelic ladder (as opposed to a molecular weight ladder). Bands could be visualized by silver staining the gel. One popular focus for fingerprinting was the D1S80 locus. As with all PCR based methods, highly degraded DNA or very small amounts of DNA may cause allelic dropout (causing a mistake in thinking a heterozygote is a homozygote) or other stochastic effects. In addition, because the analysis is done on a gel, very high number repeats may bunch together at the top of the gel, making it difficult to resolve. AmpFLP analysis can be highly automated, and allows for easy creation of phylogenetic trees based on comparing individual samples of DNA. Due to its relatively low cost and ease of set-up and operation, AmpFLP remains popular in lower income countries.
DNA family relationship analysis

Using PCR technology, DNA analysis is widely applied to determine genetic family relationships such as paternity, maternity, siblingship and other kinships.
During conception, the father's sperm cell and the mother's egg cell, each containing half the amount of DNA found in other body cells, meet and fuse to form a fertilized egg, called a zygote. The zygote contains a complete set of DNA molecules, a unique combination of DNA from both parents. This zygote divides and multiplies into an embryo and later, a full human being.
At each stage of development, all the cells forming the body contain the same DNA—half from the father and half from the mother. This fact allows the relationship testing to use all types of all samples including loose cells from the cheeks collected using buccal swabs, blood or other types of samples.
There are predictable inheritance patterns at certain locations (called loci) in the human genome, which have been found to be useful in determining identity and biological relationships. These loci contain specific DNA markers that scientists use to identify individuals. In a routine DNA paternity test, the markers used are short tandem repeats (STRs), short pieces of DNA that occur in highly differential repeat patterns among individuals.
Each person's DNA contains two copies of these markers—one copy inherited from the father and one from the mother. Within a population, the markers at each person's DNA location could differ in length and sometimes sequence, depending on the markers inherited from the parents.
The combination of marker sizes found in each person makes up his/her unique genetic profile. When determining the relationship between two individuals, their genetic profiles are compared to see if they share the same inheritance patterns at a statistically conclusive rate.
For example, the following sample report from this commercial DNA paternity testing laboratory Universal Genetics signifies how relatedness between parents and child is identified on those special markers:

The partial results indicate that the child and the alleged father's DNA match among these five markers. The complete test results show this correlation on 16 markers between the child and the tested man to enable a conclusion to be drawn as to whether or not the man is the biological father.
Each marker is assigned with a Paternity Index (PI), which is a statistical measure of how powerfully a match at a particular marker indicates paternity. The PI of each marker is multiplied with each other to generate the Combined Paternity Index (CPI), which indicates the overall probability of an individual being the biological father of the tested child relative to a randomly selected man from the entire population of the same race. The CPI is then converted into a Probability of Paternity showing the degree of relatedness between the alleged father and child.
The DNA test report in other family relationship tests, such as grandparentage and siblingship tests, is similar to a paternity test report. Instead of the Combined Paternity Index, a different value, such as a Siblingship Index, is reported.
The report shows the genetic profiles of each tested person. If there are markers shared among the tested individuals, the probability of biological relationship is calculated to determine how likely the tested individuals share the same markers due to a blood relationship.
Y-chromosome analysis
Recent innovations have included the creation of primers targeting polymorphic regions on the Y-chromosome (Y-STR), which allows resolution of a mixed DNA sample from a male and female or cases in which a differential extraction is not possible. Y-chromosomes are paternally inherited, so Y-STR analysis can help in the identification of paternally related males. Y-STR analysis was performed in the Sally Hemings controversy to determine if Thomas Jefferson had sired a son with one of his slaves.
The analysis of the Y-chromosome yields weaker results than autosomal chromosome analysis. The Y male sex-determining chromosome, as it is inherited only by males from their fathers, is almost identical along the patrilineal line. This leads to a less precise analysis than if autosomal chromosomes were testing, because of the random matching that occurs between pairs of chromosomes as zygotes are being made.[19]
Mitochondrial analysis

For highly degraded samples, it is sometimes impossible to get a complete profile of the 13 CODIS STRs. In these situations, mitochondrial DNA (mtDNA) is sometimes typed due to there being many copies of mtDNA in a cell, while there may only be 1-2 copies of the nuclear DNA. Forensic scientists amplify the HV1 and HV2 regions of the mtDNA, and then sequence each region and compare single-nucleotide differences to a reference. Because mtDNA is maternally inherited, directly linked maternal relatives can be used as match references, such as one's maternal grandmother's daughter's son. In general, a difference of two or more nucleotides is considered to be an exclusion. Heteroplasmy and poly-C differences may throw off straight sequence comparisons, so some expertise on the part of the analyst is required. mtDNA is useful in determining clear identities, such as those of missing people when a maternally linked relative can be found. mtDNA testing was used in determining that Anna Anderson was not the Russian princess she had claimed to be, Anastasia Romanov.
mtDNA can be obtained from such material as hair shafts and old bones/teeth.[20] Control mechanism based on interaction point with data. This can be determined by tooled placement in sample.
Issues with forensic DNA samples
When people think of DNA analysis they often think about shows like NCIS or CSI, which portray DNA samples coming into a lab and then instantly analyzed, followed by pulling up a picture of the suspect within minutes — the reality, however, is quite different, and perfect DNA samples are often not collected from the scene of a crime. Homicide victims are frequently left exposed to harsh conditions before they are found and objects used to commit crimes have often been handled by more than one person. The two most prevalent issues that forensic scientists encounter when analyzing DNA samples are degraded samples and DNA mixtures.
Degraded DNA
In the real world DNA labs often have to deal with DNA samples that are less than ideal. DNA samples taken from crime scenes are often degraded, which means that the DNA has started to break down into smaller fragments . Victims of homicides might not be discovered right away, and in the case of a mass casualty event it could be hard to get DNA samples before the DNA has been exposed to degradation elements.
Degradation or fragmentation of DNA at crime scenes can occur because of a number of reasons, with environmental exposure often being the most common cause. Biological samples that have been exposed to the environment can get degraded by water and enzymes called nucleases . Nucleases essentially ‘chew’ up the DNA into fragments over time and are found everywhere in nature.
Before modern PCR methods existed it was almost impossible to analyze degraded DNA samples. Methods like restriction fragment length polymorphism or RFLP , which was the first technique used for DNA analysis in forensic science, required high molecular weight DNA in the sample in order to get reliable data. High molecular weight DNA however is something that is lacking in degraded samples, as the DNA is too fragmented to accurately carry out RFLP. It wasn't until modern day PCR techniques were invented that analysis of degraded DNA samples were able to be carried out . Multiplex PCR in particular made it possible to isolate and amplify the small fragments of DNA still left in degraded samples. When multiplex PCR methods are compared to the older methods like RFLP a vast difference can be seen. Multiplex PCR can theoretically amplify less than 1ng of DNA, while RFLP had to have a least 100ng of DNA in order to carry out an analysis.[21]
In terms of a forensic approach to a degraded DNA sample, STR loci  are often amplified using PCR-based methods. Though STR loci are amplified with greater probability of success with degraded DNA, there is still the possibility that larger STR loci will fail to amplify, and therefore, would likely yield a partial profile, which results in reduced statistical weight of association in the event of a match.
MiniSTR Analysis
In instances where DNA samples are degraded, like in the case of intense fires or if all that remains are bone fragments, standard STR testing on these samples can be inadequate.  When standard STR testing is done on highly degraded samples the larger STR loci often drop out, and only partial DNA profiles are obtained. While partial DNA profiles can be a powerful tool, the random match probabilities will be larger than if a full profile was obtained.  One method that has been developed in order to analyse degraded DNA samples is to use miniSTR technology. In this new approach, primers are specially designed to bind closer to the STR region.[22]
In normal STR testing the primers will bind to longer sequences that contain the STR region within the segment. MiniSTR analysis however will just target the STR location, and this results in a DNA product that is much smaller.[22]
By placing the primers closer to the actual STR regions, there is a higher chance that successful amplification of this region will occur. Successful amplification of these STR regions can now occur and more complete DNA profiles can be obtained.  The success that smaller PCR products produce a higher success rate with highly degraded samples was first reported in 1995, when miniSTR technology was used to identify victims of the Waco fire.[23] In this case the fire at destroyed the DNA samples so badly that normal STR testing did not result in a positive ID on some of the victims.
DNA Mixtures
Mixtures are another common issue that forensic scientists face when they are analyzing unknown or questionable DNA samples. A mixture is defined as a DNA sample that contains two or more individual contributors.[24] This can often occur when a DNA sample is swabbed from an item that is handled by more than one person or when a sample contains both the victim and assailants' DNA. The presence of more than one individual in a DNA sample can make it challenging to detect individual profiles, and interpretation of mixtures should only be done by highly trained individuals. Mixtures that contain two or three individuals can be interpreted, though it will be difficult. Mixtures that contain four or more individuals are much too convoluted to get individual profiles. One common scenario in which a mixture is often obtained is in the case of sexual assault. A sample may be collected that contains material from the victim, the victim's consensual sexual partners, and the perpetrator(s).[25]
As detection methods in DNA profiling advance, forensic scientists are seeing more DNA samples that contain mixtures, as even the smallest contributor is now able to be detected by modern tests. The ease in which forensic scientists have in interpenetrating DNA mixtures largely depends on the ratio of DNA present from each individual, the genotype combinations, and total amount of DNA amplified.[26] The DNA ratio is often the most important aspect to look at in determining whether a mixture can be interpreted. For example, in the case where a DNA sample had two contributors, it would be easy to interpret individual profiles if the ratio of DNA contributed by one person was much higher than the second person. When a sample has three or more contributors, it becomes extremely difficult to determine individual profiles. Fortunately, advancements in probabilistic genotyping could make this sort of determination possible in the future. Probabilistic genotyping uses complex computer software to run through thousands of mathematical computations in order to produce statistical likelihoods of individual genotypes found in a mixture.[27] Probabilistic genotyping software that are often used in labs today include STRmix and TrueAllele.
DNA databases

An early application of a DNA database was the compilation of a Mitochondrial DNA Concordance,[28] prepared by Kevin W. P. Miller and John L. Dawson at the University of Cambridge from 1996 to 1998[29] from data collected as part of Miller's PhD thesis. There are now several DNA databases in existence around the world. Some are private, but most of the largest databases are government-controlled. The United States maintains the largest DNA database, with the Combined DNA Index System (CODIS) holding over 13 million records as of May 2018.[30] The United Kingdom maintains the National DNA Database (NDNAD), which is of similar size, despite the UK's smaller population. The size of this database, and its rate of growth, are giving concern to civil liberties groups in the UK, where police have wide-ranging powers to take samples and retain them even in the event of acquittal.[31] The Conservative–Liberal Democrat coalition partially addressed these concerns with part 1 of the Protection of Freedoms Act 2012, under which DNA samples must be deleted if suspects are acquitted or not charged, except in relation to certain (mostly serious and/or sexual) offenses. Public discourse around the introduction of advanced forensic techniques (such as genetic genealogy using public genealogy databases and DNA phenotyping approaches) has been limited, disjointed, unfocused, and raises issues of privacy and consent that may warrant the establishment of additional legal protections.[32]
The U.S. Patriot Act of the United States provides a means for the U.S. government to get DNA samples from suspected terrorists. DNA information from crimes is collected and deposited into the CODIS database, which is maintained by the FBI. CODIS enables law enforcement officials to test DNA samples from crimes for matches within the database, providing a means of finding specific biological profiles associated with collected DNA evidence.[33]
When a match is made from a national DNA databank to link a crime scene to an offender having provided a DNA sample to a database, that link is often referred to as a cold hit. A cold hit is of value in referring the police agency to a specific suspect but is of less evidential value than a DNA match made from outside the DNA Databank.[34]
FBI agents cannot legally store DNA of a person not convicted of a crime. DNA collected from a suspect not later convicted must be disposed of and not entered into the database. In 1998, a man residing in the UK was arrested on accusation of burglary. His DNA was taken and tested, and he was later released. Nine months later, this man's DNA was accidentally and illegally entered in the DNA database. New DNA is automatically compared to the DNA found at cold cases and, in this case, this man was found to be a match to DNA found at a rape and assault case one year earlier. The government then prosecuted him for these crimes. During the trial the DNA match was requested to be removed from the evidence because it had been illegally entered into the database. The request was carried out.[35]
The DNA of the perpetrator, collected from victims of rape, can be stored for years until a match is found. In 2014, to address this problem, Congress extended a bill that helps states deal with "a backlog" of evidence.[36]
Considerations when evaluating DNA evidence
As DNA profiling became a key piece of evidence in the court, defense lawyers based their arguments on statistical reasoning. For example: Given a match that had a 1 in 5 million probability of occurring by chance, the lawyer would argue that this meant that in a country of say 60 million people there were 12 people who would also match the profile. This was then translated to a 1 in 12 chance of the suspect's being the guilty one. This argument is not sound unless the suspect was drawn at random from the population of the country. In fact, a jury should consider how likely it is that an individual matching the genetic profile would also have been a suspect in the case for other reasons. Also, different DNA analysis processes can reduce the amount of DNA recovery if the procedures are not properly done. Therefore, the number of times a piece of evidence is sampled can
diminish the DNA collection efficiency. Another spurious statistical argument is based on the false assumption that a 1 in 5 million probability of a match automatically translates into a 1 in 5 million probability of innocence and is known as the prosecutor's fallacy.
When using RFLP, the theoretical risk of a coincidental match is 1 in 100 billion (100,000,000,000), although the practical risk is actually 1 in 1000 because monozygotic twins are 0.2% of the human population. Moreover, the rate of laboratory error is almost certainly higher than this, and often actual laboratory procedures do not reflect the theory under which the coincidence probabilities were computed. For example, the coincidence probabilities may be calculated based on the probabilities that markers in two samples have bands in precisely the same location, but a laboratory worker may conclude that similar—but not precisely identical—band patterns result from identical genetic samples with some imperfection in the agarose gel. However, in this case, the laboratory worker increases the coincidence risk by expanding the criteria for declaring a match. Recent studies have quoted relatively high error rates, which may be cause for concern.[37] In the early days of genetic fingerprinting, the necessary population data to accurately compute a match probability was sometimes unavailable. Between 1992 and 1996, arbitrary low ceilings were controversially put on match probabilities used in RFLP analysis rather than the higher theoretically computed ones.[38] Today, RFLP has become widely disused due to the advent of more discriminating, sensitive and easier technologies.
Since 1998, the DNA profiling system supported by The National DNA Database in the UK is the SGM+ DNA profiling system that includes 10 STR regions and a sex-indicating test. STRs do not suffer from such subjectivity and provide similar power of discrimination (1 in 1013 for unrelated individuals if using a full SGM+ profile). Figures of this magnitude are not considered to be statistically supportable by scientists in the UK; for unrelated individuals with full matching DNA profiles a match probability of 1 in a billion is considered statistically supportable. However, with any DNA technique, the cautious juror should not convict on genetic fingerprint evidence alone if other factors raise doubt. Contamination with other evidence (secondary transfer) is a key source of incorrect DNA profiles and raising doubts as to whether a sample has been adulterated is a favorite defense technique. More rarely, chimerism is one such instance where the lack of a genetic match may unfairly exclude a suspect.
Evidence of genetic relationship
It is possible to use DNA profiling as evidence of genetic relationship, although such evidence varies in strength from weak to positive. Testing that shows no relationship is absolutely certain. Further, while almost all individuals have a single and distinct set of genes, ultra-rare individuals, known as "chimeras", have at least two different sets of genes. There have been two cases of DNA profiling that falsely suggested that a mother was unrelated to her children.[39] This happens when two eggs are fertilized at the same time and fuse together to create one individual instead of twins.
Fake DNA evidence
In one case, a criminal planted fake DNA evidence in his own body: John Schneeberger raped one of his sedated patients in 1992 and left semen on her underwear. Police drew what they believed to be Schneeberger's blood and compared its DNA against the crime scene semen DNA on three occasions, never showing a match. It turned out that he had surgically inserted a Penrose drain into his arm and filled it with foreign blood and anticoagulants.
The functional analysis of genes and their coding sequences (open reading frames [ORFs]) typically requires that each ORF be expressed, the encoded protein purified, antibodies produced, phenotypes examined, intracellular localization determined, and interactions with other proteins sought.[40] In a study conducted by the life science company Nucleix and published in the journal Forensic Science International, scientists found that an in vitro synthesized sample of DNA matching any desired genetic profile can be constructed using standard molecular biology techniques without obtaining any actual tissue from that person. Nucleix claims they can also prove the difference between non-altered DNA and any that was synthesized.[41]
In the case of the Phantom of Heilbronn, police detectives found DNA traces from the same woman on various crime scenes in Austria, Germany, and France—among them murders, burglaries and robberies. Only after the DNA of the "woman" matched the DNA sampled from the burned body of a male asylum seeker in France did detectives begin to have serious doubts about the DNA evidence. It was eventually discovered that DNA traces were already present on the cotton swabs used to collect the samples at the crime scene, and the swabs had all been produced at the same factory in Austria. The company's product specification said that the swabs were guaranteed to be sterile, but not DNA-free.
DNA evidence in criminal trials

Evidence
Part of the law series
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Familial DNA searching
Familial DNA searching (sometimes referred to as "familial DNA" or "familial DNA database searching") is the practice of creating new investigative leads in cases where DNA evidence found at the scene of a crime (forensic profile) strongly resembles that of an existing DNA profile (offender profile) in a state DNA database but there is not an exact match.[42][43] After all other leads have been exhausted, investigators may use specially developed software to compare the forensic profile to all profiles taken from a state's DNA database to generate a list of those offenders already in the database who are most likely to be a very close relative of the individual whose DNA is in the forensic profile.[44] To eliminate the majority of this list when the forensic DNA is a man's, crime lab technicians conduct Y-STR analysis. Using standard investigative techniques, authorities are then able to build a family tree. The family tree is populated from information gathered from public records and criminal justice records. Investigators rule out family members' involvement in the crime by finding excluding factors such as sex, living out of state or being incarcerated when the crime was committed. They may also use other leads from the case, such as witness or victim statements, to identify a suspect. Once a suspect has been identified, investigators seek to legally obtain a DNA sample from the suspect. This suspect DNA profile is then compared to the sample found at the crime scene to definitively identify the suspect as the source of the crime scene DNA.
Familial DNA database searching was first used in an investigation leading to the conviction of Jeffrey Gafoor of the murder of Lynette White in the United Kingdom on 4 July 2003. DNA evidence was matched to Gafoor's nephew, who at 14 years old had not been born at the time of the murder in 1988. It was used again in 2004[45] to find a man who threw a brick from a motorway bridge and hit a lorry driver, killing him. DNA found on the brick matched that found at the scene of a car theft earlier in the day, but there were no good matches on the national DNA database. A wider search found a partial match to an individual; on being questioned, this man revealed he had a brother, Craig Harman, who lived very close to the original crime scene. Harman voluntarily submitted a DNA sample, and confessed when it matched the sample from the brick.[46] Currently, familial DNA database searching is not conducted on a national level in the United States, where states determine how and when to conduct familial searches. The first familial DNA search with a subsequent conviction in the United States was conducted in Denver, Colorado, in 2008, using software developed under the leadership of Denver District Attorney Mitch Morrissey and Denver Police Department Crime Lab Director Gregg LaBerge.[47] California was the first state to implement a policy for familial searching under then Attorney General, now Governor, Jerry Brown.[48] In his role as consultant to the Familial Search Working Group of the California Department of Justice, former Alameda County Prosecutor Rock Harmon is widely considered to have been the catalyst in the adoption of familial search technology in California. The technique was used to catch the Los Angeles serial killer known as the "Grim Sleeper" in 2010.[49] It wasn't a witness or informant that tipped off law enforcement to the identity of the "Grim Sleeper" serial killer, who had eluded police for more than two decades, but DNA from the suspect's own son. The suspect's son had been arrested and convicted in a felony weapons charge and swabbed for DNA the year before. When his DNA was entered into the database of convicted felons, detectives were alerted to a partial match to evidence found at the "Grim Sleeper" crime scenes. David Franklin Jr., also known as the Grim Sleeper, was charged with ten counts of murder and one count of attempted murder.[50] More recently, familial DNA led to the arrest of 21-year-old Elvis Garcia on charges of sexual assault and false imprisonment of a woman in Santa Cruz in 2008.[51] In March 2011 Virginia Governor Bob McDonnell announced that Virginia would begin using familial DNA searches.[52] Other states are expected to follow.
At a press conference in Virginia on March 7, 2011, regarding the East Coast Rapist, Prince William County prosecutor Paul Ebert and Fairfax County Police Detective John Kelly said the case would have been solved years ago if Virginia had used familial DNA searching. Aaron Thomas, the suspected East Coast Rapist, was arrested in connection with the rape of 17 women from Virginia to Rhode Island, but familial DNA was not used in the case.[53]
Critics of familial DNA database searches argue that the technique is an invasion of an individual's 4th Amendment rights.[54] Privacy advocates are petitioning for DNA database restrictions, arguing that the only fair way to search for possible DNA matches to relatives of offenders or arrestees would be to have a population-wide DNA database.[35] Some scholars have pointed out that the privacy concerns surrounding familial searching are similar in some respects to other police search techniques,[55] and most have concluded that the practice is constitutional.[56] The Ninth Circuit Court of Appeals in United States v. Pool (vacated as moot) suggested that this practice is somewhat analogous to a witness looking at a photograph of one person and stating that it looked like the perpetrator, which leads law enforcement to show the witness photos of similar looking individuals, one of whom is identified as the perpetrator.[57] Regardless of whether familial DNA searching was the method used to identify the suspect, authorities always conduct a normal DNA test to match the suspect's DNA with that of the DNA left at the crime scene.
Critics also claim that racial profiling could occur on account of familial DNA testing. In the United States, the conviction rates of racial minorities are much higher than that of the overall population. It is unclear whether this is due to discrimination from police officers and the courts, as opposed to a simple higher rate of offence among minorities. Arrest-based databases, which are found in the majority of the United States, lead to an even greater level of racial discrimination. An arrest, as opposed to conviction, relies much more heavily on police discretion.[35]
For instance, investigators with Denver District Attorney's Office successfully identified a suspect in a property theft case using a familial DNA search. In this example, the suspect's blood left at the scene of the crime strongly resembled that of a current Colorado Department of Corrections prisoner.[58] Using publicly available records, the investigators created a family tree. They then eliminated all the family members who were incarcerated at the time of the offense, as well as all of the females (the crime scene DNA profile was that of a male). Investigators obtained a court order to collect the suspect's DNA, but the suspect actually volunteered to come to a police station and give a DNA sample. After providing the sample, the suspect walked free without further interrogation or detainment. Later confronted with an exact match to the forensic profile, the suspect pleaded guilty to criminal trespass at the first court date and was sentenced to two years probation.
In Italy a familiar DNA search has been done to solve the case of the murder of Yara Gambirasio whose body was found in the bush three months after her disappearance. A DNA trace was found on the underwear of the murdered teenage near and a DNA sample was requested from a person who lived near the municipality of Brembate di Sopra and a common male ancestor was found in the DNA sample of a young man not involved in the murder. After a long investigation the father of the supposed killer was identified as Giuseppe Guerinoni, a deceased man, but his two sons born from his wife were not related to the DNA samples found on the body of Yara. After three and a half years the DNA found on the underwear of the deceased girl was matched with Massimo Giuseppe Bosetti who was arrested and accused of the murder of the 13-year-old girl.In the summer of 2016 Bosetti was found guilty and sentenced to life by the Corte d'assise of Bergamo.
Partial matches
Partial DNA matches are not searches themselves, but are the result of moderate stringency CODIS searches that produce a potential match that shares at least one allele at every locus.[59] Partial matching does not involve the use of familial search software, such as those used in the UK and United States, or additional Y-STR analysis, and therefore often misses sibling relationships. Partial matching has been used to identify suspects in several cases in the UK and United States,[60] and has also been used as a tool to exonerate the falsely accused. Darryl Hunt was wrongly convicted in connection with the rape and murder of a young woman in 1984 in North Carolina.[61] Hunt was exonerated in 2004 when a DNA database search produced a remarkably close match between a convicted felon and the forensic profile from the case. The partial match led investigators to the felon's brother, Willard E. Brown, who confessed to the crime when confronted by police. A judge then signed an order to dismiss the case against Hunt.
In Italy, partial matching has been used in the controversial murder of Yara Gambirasio, a child found dead about a month after her presumed kidnapping. In this case, the partial match has been used as the only incriminating element against the defendant, Massimo Bossetti, who has been subsequently condemned for the murder (waiting appeal by the Italian Supreme Court).
Surreptitious DNA collecting
Police forces may collect DNA samples without a suspect's knowledge, and use it as evidence. The legality of the practice has been questioned in Australia.
In the United States, it has been accepted, courts often ruling that there is no expectation of privacy, citing California v. Greenwood (1988), in which the Supreme Court held that the Fourth Amendment does not prohibit the warrantless search and seizure of garbage left for collection outside the curtilage of a home. Critics of this practice underline that this analogy ignores that "most people have no idea that they risk surrendering their genetic identity to the police by, for instance, failing to destroy a used coffee cup. Moreover, even if they do realize it, there is no way to avoid abandoning one's DNA in public."[62]
The United States Supreme Court ruled in Maryland v. King (2013) that DNA sampling of prisoners arrested for serious crimes is constitutional.[63][64][65]
In the UK, the Human Tissue Act 2004 prohibits private individuals from covertly collecting biological samples (hair, fingernails, etc.) for DNA analysis, but exempts medical and criminal investigations from the prohibition.[66]
England and Wales
Evidence from an expert who has compared DNA samples must be accompanied by evidence as to the sources of the samples and the procedures for obtaining the DNA profiles.[67] The judge must ensure that the jury must understand the significance of DNA matches and mismatches in the profiles. The judge must also ensure that the jury does not confuse the match probability (the probability that a person that is chosen at random has a matching DNA profile to the sample from the scene) with the probability that a person with matching DNA committed the crime. In 1996 R v. Doheny[68] Phillips LJ gave this example of a summing up, which should be carefully tailored to the particular facts in each case:
Members of the Jury, if you accept the scientific evidence called by the Crown, this indicates that there are probably only four or five white males in the United Kingdom from whom that semen stain could have come. The Defendant is one of them. If that is the position, the decision you have to reach, on all the evidence, is whether you are sure that it was the Defendant who left that stain or whether it is possible that it was one of that other small group of men who share the same DNA characteristics.

Juries should weigh up conflicting and corroborative evidence, using their own common sense and not by using mathematical formulae, such as Bayes' theorem, so as to avoid "confusion, misunderstanding and misjudgment".[69]
Presentation and evaluation of evidence of partial or incomplete DNA profiles
In R v Bates,[70] Moore-Bick LJ said:
We can see no reason why partial profile DNA evidence should not be admissible provided that the jury are made aware of its inherent limitations and are given a sufficient explanation to enable them to evaluate it. There may be cases where the match probability in relation to all the samples tested is so great that the judge would consider its probative value to be minimal and decide to exclude the evidence in the exercise of his discretion, but this gives rise to no new question of principle and can be left for decision on a case by case basis. However, the fact that there exists in the case of all partial profile evidence the possibility that a "missing" allele might exculpate the accused altogether does not provide sufficient grounds for rejecting such evidence. In many there is a possibility (at least in theory) that evidence that would assist the accused and perhaps even exculpate him altogether exists, but that does not provide grounds for excluding relevant evidence that is available and otherwise admissible, though it does make it important to ensure that the jury are given sufficient information to enable them to evaluate that evidence properly.[71]

DNA testing in the United States

There are state laws on DNA profiling in all 50 states of the United States.[72] Detailed information on database laws in each state can be found at the National Conference of State Legislatures website.[73]
Development of artificial DNA
In August 2009, scientists in Israel raised serious doubts concerning the use of DNA by law enforcement as the ultimate method of identification. In a paper published in the journal Forensic Science International: Genetics, the Israeli researchers demonstrated that it is possible to manufacture DNA in a laboratory, thus falsifying DNA evidence. The scientists fabricated saliva and blood samples, which originally contained DNA from a person other than the supposed donor of the blood and saliva.[74]
The researchers also showed that, using a DNA database, it is possible to take information from a profile and manufacture DNA to match it, and that this can be done without access to any actual DNA from the person whose DNA they are duplicating. The synthetic DNA oligos required for the procedure are common in molecular laboratories.[74]
The New York Times quoted the lead author, Daniel Frumkin, saying, "You can just engineer a crime scene ... any biology undergraduate could perform this".[74] Frumkin perfected a test that can differentiate real DNA samples from fake ones. His test detects epigenetic modifications, in particular, DNA methylation.[75] Seventy percent of the DNA in any human genome is methylated, meaning it contains methyl group modifications within a CpG dinucleotide context. Methylation at the promoter region is associated with gene silencing. The synthetic DNA lacks this epigenetic modification, which allows the test to distinguish manufactured DNA from genuine DNA.[74]
It is unknown how many police departments, if any, currently use the test. No police lab has publicly announced that it is using the new test to verify DNA results.[76]
Cases
In 1986, Richard Buckland was exonerated, despite having admitted to the rape and murder of a teenager near Leicester, the city where DNA profiling was first developed. This was the first use of DNA fingerprinting in a criminal investigation, and the first to prove a suspect's innocence.[77] The following year Colin Pitchfork was identified as the perpetrator of the same murder, in addition to another, using the same techniques that had cleared Buckland.[78]
In 1987, genetic fingerprinting was used in criminal court for the first time in the trial of a man accused of unlawful intercourse with a mentally handicapped 14-year-old female who gave birth to a baby.[79]
In 1987, Florida rapist Tommie Lee Andrews was the first person in the United States to be convicted as a result of DNA evidence, for raping a woman during a burglary; he was convicted on November 6, 1987, and sentenced to 22 years in prison.[80][81]
In 1988, Timothy Wilson Spencer was the first man in Virginia to be sentenced to death through DNA testing, for several rape and murder charges. He was dubbed "The South Side Strangler" because he killed victims on the south side of Richmond, Virginia. He was later charged with rape and first-degree murder and was sentenced to death. He was executed on April 27, 1994. David Vasquez, initially convicted of one of Spencer's crimes, became the first man in America exonerated based on DNA evidence.
In 1989, Chicago man Gary Dotson was the first person whose conviction was overturned using DNA evidence.
In 1991, Allan Legere was the first Canadian to be convicted as a result of DNA evidence, for four murders he had committed while an escaped prisoner in 1989. During his trial, his defense argued that the relatively shallow gene pool of the region could lead to false positives.
In 1992, DNA evidence was used to prove that Nazi doctor Josef Mengele was buried in Brazil under the name Wolfgang Gerhard.
In 1992, DNA from a palo verde tree was used to convict Mark Alan Bogan of murder. DNA from seed pods of a tree at the crime scene was found to match that of seed pods found in Bogan's truck.  This is the first instance of plant DNA admitted in a criminal case.[82][83][84]
In 1993, Kirk Bloodsworth was the first person to have been convicted of murder and sentenced to death, whose conviction was overturned using DNA evidence.
The 1993 rape and murder of Mia Zapata, lead singer for the Seattle punk band The Gits, was unsolved nine years after the murder. A database search in 2001 failed, but the killer's DNA was collected when he was arrested in Florida for burglary and domestic abuse in 2002.
The science was made famous in the United States in 1994 when prosecutors heavily relied on DNA evidence allegedly linking O. J. Simpson to a double murder. The case also brought to light the laboratory difficulties and handling procedure mishaps that can cause such evidence to be significantly doubted.
In 1994, Royal Canadian Mounted Police (RCMP) detectives successfully tested hairs from a cat known as Snowball, and used the test to link a man to the murder of his wife, thus marking for the first time in forensic history the use of non-human animal DNA to identify a criminal (plant DNA was used in 1992, see above).
In 1994, the claim that Anna Anderson was Grand Duchess Anastasia Nikolaevna of Russia was tested after her death using samples of her tissue that had been stored at a Charlottesville, Virginia hospital following a medical procedure. The tissue was tested using DNA fingerprinting, and showed that she bore no relation to the Romanovs.[85]
In 1994, Earl Washington, Jr., of Virginia had his death sentence commuted to life imprisonment a week before his scheduled execution date based on DNA evidence. He received a full pardon in 2000 based on more advanced testing.[86] His case is often cited by opponents of the death penalty.
In 1995, the British Forensic Science Service carried out its first mass intelligence DNA screening in the investigation of the Naomi Smith murder case.
In 1998, Richard J. Schmidt was convicted of attempted second-degree murder when it was shown that there was a link between the viral DNA of the human immunodeficiency virus (HIV) he had been accused of injecting in his girlfriend and viral DNA from one of his patients with AIDS. This was the first time viral DNA fingerprinting had been used as evidence in a criminal trial.
In 1999, Raymond Easton, a disabled man from Swindon, England, was arrested and detained for seven hours in connection with a burglary. He was released due to an inaccurate DNA match. His DNA had been retained on file after an unrelated domestic incident some time previously.[87]
In 2000 Frank Lee Smith was proved innocent by DNA profiling of the murder of an eight-year-old girl after spending 14 years on death row in Florida, USA. However he had died of cancer just before his innocence was proven.[88] In view of this the Florida state governor ordered that in future any death row inmate claiming innocence should have DNA testing.[86]
In May 2000 Gordon Graham murdered Paul Gault at his home in Lisburn, Northern Ireland. Graham was convicted of the murder when his DNA was found on a sports bag left in the house as part of an elaborate ploy to suggest the murder occurred after a burglary had gone wrong. Graham was having an affair with the victim's wife at the time of the murder. It was the first time Low Copy Number DNA was used in Northern Ireland.[89]
In 2001, Wayne Butler was convicted for the murder of Celia Douty. It was the first murder in Australia to be solved using DNA profiling.[90][91]
In 2002, the body of James Hanratty, hanged in 1962 for the "A6 murder", was exhumed and DNA samples from the body and members of his family were analysed.  The results convinced Court of Appeal judges that Hanratty's guilt, which had been strenuously disputed by campaigners, was proved "beyond doubt".[92] Paul Foot and some other campaigners continued to believe in Hanratty's innocence and argued that the DNA evidence could have been contaminated, noting that the small DNA samples from items of clothing, kept in a police laboratory for over 40 years "in conditions that do not satisfy modern evidential standards", had had to be subjected to very new amplification techniques in order to yield any genetic profile.[93] However, no DNA other than Hanratty's was found on the evidence tested, contrary to what would have been expected had the evidence indeed been contaminated.[94]
In 2002, DNA testing was used to exonerate Douglas Echols, a man who was wrongfully convicted in a 1986 rape case. Echols was the 114th person to be exonerated through post-conviction DNA testing.
In August 2002, Annalisa Vincenzi was shot dead in Tuscany. Bartender Peter Hamkin, 23, was arrested, in Merseyside in March 2003 on an extradition warrant heard at Bow Street Magistrates' Court in London to establish whether he should be taken to Italy to face a murder charge. DNA "proved" he shot her, but he was cleared on other evidence.[95]
In 2003, Welshman Jeffrey Gafoor was convicted of the 1988 murder of Lynette White, when crime scene evidence collected 12 years earlier was re-examined using STR techniques, resulting in a match with his nephew.[96] This may be the first known example of the DNA of an innocent yet related individual being used to identify the actual criminal, via "familial searching".
In March 2003, Josiah Sutton was released from prison after serving four years of a twelve-year sentence for a sexual assault charge. Questionable DNA samples taken from Sutton were retested in the wake of the Houston Police Department's crime lab scandal of mishandling DNA evidence.
In June 2003, because of new DNA evidence, Dennis Halstead, John Kogut and John Restivo won a re-trial on their murder conviction, their convictions were struck down and they were released.[97] The three men had already served eighteen years of their thirty-plus-year sentences.
The trial of Robert Pickton (convicted in December 2003) is notable in that DNA evidence is being used primarily to identify the victims, and in many cases to prove their existence.
In 2004, DNA testing shed new light into the mysterious 1912 disappearance of Bobby Dunbar, a four-year-old boy who vanished during a fishing trip. He was allegedly found alive eight months later in the custody of William Cantwell Walters, but another woman claimed that the boy was her son, Bruce Anderson, whom she had entrusted in Walters' custody. The courts disbelieved her claim and convicted Walters for the kidnapping. The boy was raised and known as Bobby Dunbar throughout the rest of his life. However, DNA tests on Dunbar's son and nephew revealed the two were not related, thus establishing that the boy found in 1912 was not Bobby Dunbar, whose real fate remains unknown.[98]
In 2005, Gary Leiterman was convicted of the 1969 murder of Jane Mixer, a law student at the University of Michigan, after DNA found on Mixer's pantyhose was matched to Leiterman. DNA in a drop of blood on Mixer's hand was matched to John Ruelas, who was only four years old in 1969 and was never successfully connected to the case in any other way. Leiterman's defense unsuccessfully argued that the unexplained match of the blood spot to Ruelas pointed to cross-contamination and raised doubts about the reliability of the lab's identification of Leiterman.[99][100][101]
In December 2005, Evan Simmons was proven innocent of a 1981 attack on an Atlanta woman after serving twenty-four years in prison. Mr. Clark is the 164th person in the United States and the fifth in Georgia to be freed using post-conviction DNA testing.
In November 2008, Anthony Curcio was arrested for masterminding one of the most elaborately planned armored car heists in history.  DNA evidence linked Curcio to the crime.[102]
In March 2009, Sean Hodgson—convicted of 1979 killing of Teresa De Simone, 22, in her car in Southampton—was released after tests proved DNA from the scene was not his. It was later matched to DNA retrieved from the exhumed body of David Lace. Lace had previously confessed to the crime but was not believed by the detectives. He served time in prison for other crimes committed at the same time as the murder and then committed suicide in 1988.[103]
In 2012, familial DNA profiling led to Alice Collins Plebuch's unexpected discovery that her ancestral bloodline was not purely Irish, as she had previously been led to believe, but that her heritage also contained European Jewish, Middle Eastern and Eastern European. This led her into an extensive genealogy investigation which resulted in her uncovering the genetic family of her adopted father.[104][105]
In 2016 Anthea Ring, abandoned as baby, was able to use a DNA sample and DNA matching database to discover her deceased mother's identity and roots in County Mayo, Ireland. A recently developed forensic test was subsequently used to capture DNA from saliva left on old stamps and envelopes by her suspected father, uncovered through painstaking genealogy research. The DNA in the first three samples was too degraded to use. However, on the fourth, more than enough DNA was found. The test, which has a degree of accuracy acceptable in UK courts, proved that a man named Patrick Coyne was her biological father.[106][107]
In 2018 the Buckskin girl (a body found in 1981 in Ohio) was identified as Marcia King from Arkansas using DNA genealogical techniques[108]
In 2018 Joseph James DeAngelo was arrested as the main suspect for the Golden State Killer using DNA and genealogy techniques.[109]
In 2018 William Earl Talbot, II was arrested as a suspect for the 1987 murder of Jay Cook and Tanya Van Cuylenborg with the assistance of DNA genealogical  techniques .  The same genetic genealogist that helped in this case also helped police with 18 other arrests in 2018.[110]
DNA evidence as evidence to prove rights of succession to British titles
DNA testing is used to establish the right of succession to British titles.[111]
Cases:
Baron Moynihan
Pringle baronets
See also

DNA barcoding
DNA database
National DNA database
DNA paternity testing
Capillary electrophoresis (CE)
Forensic identification
Full genome sequencing
Gene mapping
Genealogical DNA test
Harvey v. Horan
Identification (biology)
Kinship analysis
Maryland v. King
Phantom of Heilbronn
Project Innocence
Restriction fragment length polymorphism (RFLP)
Ribotyping
Short tandem repeat (STR)
International Society for Forensic Genetics
International Society of Genetic Genealogy

Further reading

—Blog that tracks scientific and legal developments pertinent to forensic DNA profiling
—PBS.org
—A place to learn typing techniques by simulating them

, Winston & Strawn LLP/The Innocence Project
 United States Department of Justice


Swiss German (Standard German: Schweizerdeutsch, Alemannic German: Schwyzerdütsch, Schwiizertüütsch, Schwizertitsch Mundart,[note 1] and others) is any of the Alemannic dialects spoken in the German-speaking part of Switzerland and in some Alpine communities in Northern Italy bordering Switzerland. Occasionally, the Alemannic dialects spoken in other countries are grouped together with Swiss German as well, especially the dialects of Liechtenstein and Austrian Vorarlberg, which are closely associated to Switzerland's.
Linguistically, Swiss German forms no unity. The linguistic division of Alemannic is rather into Low, High and Highest Alemannic, varieties all of which are spoken both inside and outside Switzerland. The only exception within German-speaking Switzerland is the municipality of Samnaun where a Bavarian dialect is spoken. The reason "Swiss German" dialects constitute a special group is their almost unrestricted use as a spoken language in practically all situations of daily life, whereas the use of the Alemannic dialects in other countries is restricted or even endangered.
The dialects of Swiss German must not be confused with Swiss Standard German, the variety of Standard German used in Switzerland. Most people in Germany do not understand Swiss German. Therefore, when an interview with a Swiss German speaker is shown on German television, subtitles are required.[3] Although Swiss German is the native language, from age 6, Swiss school students additionally learn Swiss Standard German at school and are thus capable of understanding, writing and speaking Standard German with varying abilities mainly based on the level of education.
Use
Unlike most regional languages in modern Europe, Swiss German is the spoken everyday language for the majority of all social levels in industrial cities, as well as in the countryside. Using the dialect conveys neither social nor educational inferiority and is done with pride.[4] There are a few settings where speaking Standard German is demanded or polite, e.g., in education (but not during breaks in school lessons, where the teachers will speak in the dialect with students), in multilingual parliaments (the federal parliaments and a few cantonal and municipal ones), in the main news broadcast or in the presence of non-Alemannic speakers. This situation has been called a "medial diglossia", since the spoken language is mainly the dialect, whereas the written language is mainly (the Swiss variety of) Standard German.
In 2014, about 87% of the people living in German-speaking Switzerland were using Swiss German in their everyday lives.[5]
Swiss German is intelligible to speakers of other Alemannic dialects, but largely unintelligible to speakers of Standard German without adequate prior exposure, including for French- or Italian-speaking Swiss who learn Standard German at school. Swiss German speakers on TV or in films are thus usually dubbed or subtitled if shown in Germany.
Dialect rock is a music genre using the language; many Swiss rock bands, however, alternatively rather sing in English.
The Swiss Amish of Adams County, Indiana and their daughter settlements also use Swiss German.
Variation and distribution
Swiss German is a regional or political umbrella term, not a linguistic unity. For all dialects, there are idioms spoken outside Switzerland that are more closely related to them than some Swiss German dialects. The main linguistic divisions within Swiss German are those of Low, High and Highest Alemannic, and mutual intelligibility across those groups is almost fully seamless, though with some minor exceptions, mainly regarding vocabulary. Low Alemannic is only spoken in the northernmost parts of Switzerland, in Basel and around Lake Constance. High Alemannic is spoken in most of the Swiss Plateau, and is divided in an eastern and a western group. Highest Alemannic is spoken in the Alps.

Low Alemannic
Basel German in Basel-Stadt (BS), closely related to Alsatian
High Alemannic
western
Bernese German, in the Swiss Plateau parts of Bern (BE)
dialects of Basel-Landschaft (BL)
dialects of Solothurn (SO)
dialects of the western part of Aargau (AG)
in a middle position between eastern and western are
dialects in the eastern part of Aargau (AG)
dialects of Lucerne (LU)
dialects of Zug (ZG)
Zürich German, in Zürich (ZH)
eastern
dialects of St. Gallen (SG)
dialects of Appenzell (AR & AI)
dialects of Thurgau (TG)
dialects of Schaffhausen (SH)
dialects in parts of Graubünden (GR)
Highest Alemannic
dialects in parts of Canton of Fribourg (FR)
dialects of the Bernese Oberland (BE)
dialects of Unterwalden (OW & NW) and Uri (UR)
dialects of Schwyz (SZ)
dialects of Glarus (GL)
Walliser German in parts of the Valais (VS)
Walser German: Via the medieval migration of the Walser, Highest Alemannic spread to pockets of what are now parts of northern Italy (P), the north west of Ticino (TI), parts of Graubünden (GR), Liechtenstein and Vorarlberg.
Each dialect is separable into numerous local subdialects, sometimes down to a resolution of individual villages. Speaking the dialect is an important part of regional, cantonal and national identities. In the more urban areas of the Swiss plateau, regional differences are fading due to increasing mobility, and a growing population of non-Alemannic descent. Despite the varied dialects, the Swiss can still understand one another, but may particularly have trouble understanding Walliser dialects.
History

Most Swiss German dialects, being High German dialects, have completed the High German consonant shift (synonyms: Second Germanic consonant shift, High German sound shift[6][7]), that is, they have not only changed t to [t͡s] or [s] and p to [p͡f] or [f], but also k to [k͡x] or [x]. There are, however, exceptions, namely the idioms of Chur and Basel. Basel German is a Low Alemannic dialect (mostly spoken in Germany near the Swiss border), and Chur German is basically High Alemannic without initial [x] or [k͡x].
Examples:

The High German consonant shift happened between the fourth and 9th centuries south of the Benrath line, separating High German from Low German, where high refers to the geographically higher regions of the German-speaking area of those days (combining Upper German and Central German varieties - also referring to their geographical locations).
North of the Benrath line up to the North Sea, this consonant shift did not happen.
The Walser migration, going on between the 12th and 13th centuries, spread upper Wallis varieties towards the east and south, into Grisons and even further to western Austria and northern Italy. Informally, a distinction is made between the German-speaking people living in the canton of Valais, the Walliser, and the migrated ones, the Walsers (to be found mainly in Graubünden, Vorarlberg in Western Austria, Ticino in South Switzerland, south of the Monte Rosa mountain chain in Italy (e.g. in Issime in the Aosta valley), Tirol in North Italy, and Allgäu in Bavaria).
Generally, the Walser communities were situated on higher alpine regions, so were able to stay independent of the reigning forces of those days, who did not or were not able to follow and monitor them all the time necessary at these hostile and hard to survive areas. So, the Walser were pioneers of the liberalization from serfdom and feudalism. And, Walser villages are easily distinguishable from Grisonian ones, since Walser houses are made of wood instead of stone.
Phonology
Consonants

Like all other Southern German dialects, Swiss German dialects have no voiced obstruents. However, they have an opposition of consonant pairs such as [t] and [d] or [p] and [b]. Traditionally, that distinction is said to be a distinction of fortis and lenis, but it has been claimed to be a distinction of quantity.[8]
Swiss German keeps the fortis–lenis opposition at the end of words. There can be minimal pairs such as graad [ɡ̊raːd̥] 'straight' and Graat [ɡ̊raːt] 'arête' or bis [b̥ɪz̥] 'be (imp.)' and Biss [b̥ɪs] 'bite'. That distinguishes Swiss German and Swiss Standard German from German Standard German, which neutralizes the fortis–lenis opposition at the ends of words. The phenomenon is usually called final-obstruent devoicing even though, in the case of German, phonetic voice may not be involved.
Swiss German /p, t, k/ are not aspirated. Aspirated [pʰ, tʰ, kʰ] have (in most dialects) secondarily developed by combinations of prefixes with word-initial /h/ or by borrowings from other languages (mainly Standard German): /ˈphaltə/ 'keep' (standard German behalten [bəˈhaltn̩]); /ˈtheː/ 'tea' (standard German Tee [ˈtʰeː]); /ˈkhalt/ 'salary' (standard German Gehalt [ɡəˈhalt]). In the dialects of Basel and Chur, aspirated /k/ is also present in native words. All typically-voiced consonant sounds are voiceless. Stop sounds being /b̥ d̥ ɡ̊/, and fricatives as /v̥ z̥ ɣ̊ ʒ̊/.
Unlike Standard German, Swiss German /x/ does not have the allophone [ç] but is typically [x], with the allophone [χ]. The typical Swiss shibboleth features this sound: Chuchichäschtli ('kitchen cupboard'), pronounced [ˈχuχːiˌχæʃtli].
Most Swiss German dialects have gone through the Alemannic n-apocope, which has led to the loss of final -n in words such as Garte 'garden' (standard German Garten) or mache 'to make' (standard German machen). In some Highest Alemannic dialects, the n-apocope has also been effective in consonant clusters, for instance in Hore 'horn' (High Alemannic Horn) or däiche 'to think' (High Alemannic dänke). Only the Highest Alemannic dialects of the Lötschental and of the Haslital have preserved the -n.
The phoneme /r/ is pronounced as an alveolar trill [r] in many dialects, but some dialects, especially in the Northeast or in the Basel region, have a uvular trill [ʀ], like in many German varieties of Germany.
A labiodental approximant [ʋ] is used in Swiss German, as the [v] sound is present in Standard German.
Vowels

Most Swiss German dialects have rounded front vowels, unlike other High German dialects.[9] Only in Low Alemannic dialects of northwestern Switzerland (mainly Basel) and in Walliser dialects have rounded front vowels been unrounded. In Basel, rounding is being reintroduced because of the influence of other Swiss German dialects.
Like Bavarian dialects, Swiss German dialects have preserved the opening diphthongs of Middle High German: /iə̯, uə̯, yə̯/: in /liə̯b̥/ 'lovely' (standard German lieb but pronounced /liːp/); /huə̯t/ 'hat' (standard German Hut /huːt/); /xyə̯l/ 'cool' (Standard German kühl /kyːl/). Some diphthongs have become unrounded in several dialects.
Like in Low German, most Swiss German dialects have preserved the old West-Germanic monophthongs /iː, uː, yː/: /pfiːl/ 'arrow' (Standard German Pfeil /pfaɪ̯l/); /b̥uːx/ 'belly' (Standard German Bauch /baʊ̯x/); /z̥yːlə/ 'pillar' (Standard German Säule /zɔʏ̯lə/). A few Alpine dialects show diphthongization, like in Standard German, especially some dialects of Unterwalden and Schanfigg (Graubünden) and the dialect of Issime (Piedmont).

Some Western Swiss German dialects like Bernese German have preserved the old diphthongs /ei̯, ou̯/, but the other dialects have /ai̯, au̯/ like Standard German or /æi̯, æu̯/. Zurich German, and some other dialects distinguish primary diphthongs from secondary ones that arose in hiatus: Zurich German /ai̯, au̯/ from Middle High German /ei̯, ou̯/ versus Zurich German /ei̯, ou̯/ from Middle High German /iː, uː/; Zurich German /bai̯, frau̯/ 'leg, woman' from Middle High German bein, vrouwe versus Zurich German /frei̯, bou̯/ 'free, building' from Middle High German frī, būw.
Suprasegmentals
In many Swiss German dialects, consonant length and vowel length are independent from each other, unlike other modern Germanic languages. Here are examples from Bernese German:

Lexical stress is more often on the first syllable than in Standard German, even in French loans like [ˈmɛrsːi] or [ˈmersːi] "thanks". However, there are many different stress patterns, even within dialects. Bernese German has many words that are stressed on the first syllable: [ˈkaz̥inɔ] 'casino' while Standard German has [kʰaˈziːno]. However, no Swiss German dialect is as consistent as Icelandic in that respect.
Grammar
The grammar of Swiss dialects has some specialties compared to Standard German:
There is no preterite indicative (yet there is a preterite subjunctive).
The preterite is replaced by perfect constructs (this also happens in spoken Standard German, particularly in Southern Germany and Austria).
It is still possible to form pluperfect phrases, by applying the perfect construct twice to the same sentence.
There is no genitive case, though certain dialects have preserved a possessive genitive (for instance in rural Bernese German). The genitive case is replaced by two constructions: The first of these is often acceptable in Standard German as well: possession + Prp. vo (std. German von) + possessor: es Buech vomene Profässer vs. Standard German ein Buch von einem Professor ("a book of a professor"), s Buech vom Profässer vs. Standard German das Buch des Professors ("the professor's book"). The second is still frowned on where it appears in Standard German (from dialects and spoken language): dative of the possessor + the possessive pronoun referring to the possessor + possession: em Profässer sis Buech ("the professor his book").[10]
The order within verb groups may vary, e.g. wo du bisch cho/wo du cho bisch vs. standard German als du gekommen bist "when you have come/came".[11]
All relative clauses are introduced by the relative particle wo (‘where’), never by the relative pronouns der, die, das, welcher, welches as in Standard German, e.g. ds Bispil, wo si schrybt vs. Standard German das Beispiel, das sie schreibt (‘the example that she writes’); ds Bispil, wo si dra dänkt vs. Standard German das Beispiel, woran sie denkt (‘the example that she thinks of’). Whereas the relative particle wo replaces the Standard German relative pronouns in the Nom. (subject) and Acc. (direct object) without further complications, in phrases where wo plays the role of an indirect object, a prepositional object, a possessor or an adverbial adjunct it has to be taken up later in the relative clause by reference of (prp. +) the personal pronoun (if wo refers to a person) or the pronominal adverb (if wo refers to a thing). E.g. de Profässer won i der s Buech von em zeiget ha ("the professor whose book I showed you"), de Bärg wo mer druf obe gsii sind ("the mountain that we were upon").[10]
In combinations with other verbs, the verbs gah or goh "go", cho "come", la or lo "let" and aafa or aafo "begin" reduplicate, prefixed to the main verb.

example:SichuntüseChrischtboumchoschmücke.literal translation:shecomesourChristmas treecomedecoratetranslationShe comes to decorate our Christmas tree.standard German:Sie kommt unseren Christbaum schmücken.

example:Silatnenidlaschlafe.literal translation:sheletshimnotletsleeptranslation:She doesn't let him sleep.standard German:Sie lässt ihn nicht schlafen.
This is probably a generalization of a close association of these verbs with the following verb in perfect or modal verb constructions:

perfect:Sihetnenidla schlafe.literal translation:shehashimnotlet sleeptranslation:She hasn't/didn't let him sleep.standard German:Sie hat ihn nicht schlafen lassen. or Sie ließ ihn nicht schlafen.

modal verb:Siwotnenidla schlafe.literal translation:shewantshimnotlet sleeptranslation:She doesn't want to let him sleep.standard German:Sie will ihn nicht schlafen lassen.
Vocabulary
The vocabulary is varied, especially in rural areas: many specialized terms have been retained, e.g., regarding cattle or weather. In the cities, much of the rural vocabulary has been lost. A Swiss German greeting is Grüezi, from Gott grüez-i (Standard German Gott grüsse Euch) or "God bless you".[12]
Most word adoptions come from Standard German. Many of these are now so common that they have totally replaced the original Swiss German words, e.g. the words Hügel 'hill' (instead of Egg, Bühl), Lippe 'lip' (instead of Lefzge). Others have replaced the original words only in parts of Switzerland, e.g., Butter 'butter' (originally called Anken in most of Switzerland). Virtually any Swiss Standard German word can be borrowed into Swiss German, always adapted to Swiss German phonology. However, certain Standard German words are never used in Swiss German, for instance Frühstück 'breakfast', niedlich 'cute' or zu hause 'at home'; instead, the native words Zmorge, härzig and dehei are used.
Swiss dialects have quite a few words from French and Italian, which are perfectly assimilated. Glace (ice cream) for example is pronounced /ɡlas/ in French but [ˈɡ̊lasːeː] or [ˈɡ̊lasːə] in many Swiss German dialects. The French word for 'thank you', merci, is also used as in merci vilmal, literally "thanks many times". Possibly, these words are not direct adoptions from French but survivors of the once more numerous French loanwords in Standard German, many of which have fallen out of use in Germany.
In recent years, Swiss dialects have also taken some English words which already sound very Swiss, e.g., [ˈfuːd̥ə] ('to eat', from "food"), [ɡ̊ei̯mə] ('to play computer games', from "game") or [ˈz̥nœːb̥ə] or [ˈb̥oːrd̥ə] – ('to snowboard', from "snowboard"). These words are probably not direct loanwords from English but have been adopted through standard German intermediation. While most of those loanwords are of recent origin, some have been in use for decades, e.g. [ˈ(t)ʃutːə] (to play football, from "shoot").
There are also a few English words which are modern adoptions from Swiss German. The dishes müesli, and rösti have become English words, as did loess (fine grain), flysch (sandstone formation), kepi, landamman, kilch, schiffli, and putsch in a political sense. The term bivouac is sometimes explained as originating from Swiss German,[13] while printed etymological dictionaries (e.g. the German Kluge or Knaurs Etymological Dictionary) derive it from Low German instead.
Literature
Written forms that were mostly based on the local Alemannic varieties, thus similar to Middle High German, were only gradually replaced by the forms of New High German. This replacement took from the 15th to 18th centuries to complete. In the 16th century, the Alemannic forms of writing were considered the original, truly Swiss forms, whereas the New High German forms were perceived as foreign innovations. The innovations were brought about by the printing press and were also associated with Lutheranism. An example of the language shift is the Froschauer Bible: Its first impressions after 1524 were largely written in an Alemannic language, but since 1527, the New High German forms were gradually adopted. The Alemannic forms were longest preserved in the chancelleries, with the chancellery of Bern being the last to adopt New High German in the second half of the 18th century.[14]
Today all formal writing, newspapers, books and much informal writing is done in Swiss Standard German, which is usually called Schriftdeutsch (written German). Certain dialectal words are accepted regionalisms in Swiss Standard German and are also sanctioned by the Duden, e.g., Zvieri (afternoon snack). Swiss Standard German is virtually identical to Standard German as used in Germany, with most differences in pronunciation, vocabulary, and orthography. For example, Swiss Standard German always uses a double s (ss) instead of the eszett (ß).
There are no official rules of Swiss German orthography. The orthographies used in the Swiss-German literature can be roughly divided into two systems: Those that try to stay as close to standard German spelling as possible and those that try to represent the sounds as well as possible. The so-called Schwyzertütschi Dialäktschrift was developed by Eugen Dieth, but knowledge of these guidelines is limited mostly to language experts. Furthermore, the spellings originally proposed by Dieth included some special signs not found on a normal keyboard, such as ⟨ʃ⟩ instead of ⟨sch⟩ for [ʃ] or ⟨ǜ⟩ instead of ⟨ü⟩ for [ʏ]. In 1986, a revised version of the Dieth-Schreibung was published, designed to be written "on a normal typewriter".[15]
A few letters are used differently from the Standard German rules:
⟨k⟩ (and ⟨ck⟩) are used for the affricate /kx/.
⟨gg⟩ is used for the unaspirated fortis /k/.
⟨y⟩ (and sometimes ⟨yy⟩) traditionally stands for the /iː/ (in many dialects shortened to /i/, but still with closed quality) that corresponds to Standard German /aɪ̯/, e.g. in Rys ‘rice’ (standard German Reis /raɪ̯s/) vs. Ris ‘giant’ (standard German /riːzə/). This usage goes back to an old ij-ligature. Many writers, however, don't use ⟨y⟩, but ⟨i⟩/⟨ii⟩, especially in the dialects that have lost distinction between these sounds, compare Zürich German Riis /riːz̥/ ‘rice’ or 'giant' to Bernese German Rys /riːz̥/ 'rice' vs. Ris /rɪːz̥/ (‘giant’). Some use even ⟨ie⟩, influenced by Standard German spelling, which leads to confusion with ⟨ie⟩ for /iə̯/.
⟨w⟩ represents [ʋ], slightly different from Standard German as [v].
⟨ä⟩ usually represents [æ], and can also represent [ə] or [ɛ].
⟨ph⟩ represents [pʰ], ⟨th⟩ represents [tʰ], and ⟨gh⟩ represents [kʰ].
Since [ei] is written as ⟨ei⟩, [ai] is written as ⟨äi⟩, though in eastern Switzerland ⟨ei⟩ is often used for both of these phonemes.
Since the 19th century, a considerable body of Swiss German literature has accumulated. The earliest works were in Zurich German (Johann Martin Usteri, Jakob Stutz); the works of Jeremias Gotthelf which were published at the same time are in Swiss Standard German, but use many expressions of Bernese German. Some of the more important dialect writing authors and their works are:
Anna Maria Bacher (born 1947), Z Kschpel fam Tzit; Litteri un Schattä; Z Tzit fam Schnee (South Walser German of Formazza/Pomatt)
Albert Bächtold (1891–1981), De goldig Schmid; Wält uhni Liecht; De Studänt Räbme; Pjotr Ivanowitsch (Schaffhausen dialect of Klettgau)
Ernst Burren (born 1944), Dr Schtammgascht; Näschtwermi (Solothurn dialect)
August Corrodi (1826–1885), De Herr Professer; De Herr Vikari; De Herr Dokter, translation of Plautus's Mostellaria (Zurich dialect)
Barbara Egli (1918–2005), Wildi Chriesi (Zurich Oberland dialect)
Fritz Enderlin (1883–1971), De Sonderbunds-Chrieg, translated from C. F. Ramuz's French poem La Grande Guerre du Sondrebond (Upper Thurgovian dialect)
Martin Frank (born 1950), Ter Fögi ische Souhung; La Mort de Chevrolet (Bernese dialect with Zurich interferences)
Simon Gfeller (1868–1943), Ämmegrund; Drätti, Müetti u der Chlyn; Seminarzyt (Bernese dialect of Emmental)
Jeremias Gotthelf (1797–1854), only parts of his works are written in dialect (Bernese dialect)
Paul Haller (1882–1920), Maria und Robert (Western Aargau dialect)
Frida Hilty-Gröbli (1893–1957), Am aalte Maartplatz z Sant Galle; De hölzig Matroos (St Gall dialect)
Josef Hug (1903–1985), S Gmaiguet; Dunggli Wolgga ob Salaz (Graubünden Rhine Valley dialect)
Thomas Hürlimann (born 1950), Dr Franzos im Ybrig, loosely based on Morel's play
Guy Krneta (born 1964), Furnier (collection of short stories), Zmittst im Gjätt uss (prose), Ursle (Bernese dialect)
Michael Kuoni (1838–1891), Bilder aus dem Volksleben des Vorder-Prättigau's (Graubünden Walser dialect of Prättigau)
Maria Lauber (1891–1973), Chüngold; Bletter im Luft; Der jung Schuelmiischter (Bernese Oberland dialect)
Pedro Lenz (born 1965), Plötzlech hets di am Füdle (Bernese Dialect)
Meinrad Lienert (1865–1933), Flüeblüemli; 's Mireli; Der Waldvogel (Schwyz dialect of Einsiedeln)
Carl Albert Loosli (1877–1959), Mys Dörfli; Mys Ämmitaw; Wi's öppe geit! (Bernese dialect of Emmental)
Kurt Marti (born 1921), Vierzg Gedicht ir Bärner Umgangssprache; Rosa Loui (Bernese dialect)
Mani Matter (1936–1972), songwriter (Bernese dialect)
Traugott Meyer (1895–1959), 's Tunnälldorf; Der Gänneral Sutter (Basel-Landschaft dialect)
Gall Morel (1803–1872), Dr Franzos im Ybrig (Schwyz German of Iberg)
Viktor Schobinger (born 1934), Der Ääschme trifft simpatisch lüüt and a lot of other Züri Krimi (Zurich dialect)
Caspar Streiff (1853–1917), Der Heiri Jenni im Sunnebärg (Glarus dialect)
Jakob Stutz (1801–1877), Gemälde aus dem Volksleben; Ernste und heitere Bilder aus dem Leben unseres Volkes (Zurich Oberland dialect)
Rudolf von Tavel (1866–1934), Ring i der Chetti; Gueti Gschpane; Meischter und Ritter; Der Stärn vo Buebebärg; D’Frou Kätheli und ihri Buebe; Der Frondeur; Ds velorene Lied; D’Haselmuus; Unspunne; Jä gäl, so geit’s!; Der Houpme Lombach; Götti und Gotteli; Der Donnergueg; Veteranezyt; Heinz Tillman; Die heilige Flamme; Am Kaminfüür; Bernbiet; Schweizer daheim und draußen; Simeon und Eisi; Geschichten aus dem Bernerland (Bernese dialect)[16]
Alfred Tobler (1845–1923), Näbes oß mine Buebejohre (Appenzell dialect)
Johann Martin Usteri (1763–1827), Dichtungen in Versen und Prosa (Zurich German)
Hans Valär (1871–1947), Dr Türligiiger (Graubünden Walser dialect of Davos)
Bernhard Wyss (1833–1889), Schwizerdütsch. Bilder aus dem Stilleben unseres Volkes (Solothurn dialect)
Parts of the Bible were translated in different Swiss German dialects, e.g.:[17]
Ds Nöie Teschtamänt bärndütsch (Bernese New Testament, translated by Hans and Ruth Bietenhard, 1989)
Ds Alte Teschtamänt bärndütsch (parts of the Old Testament in Bernese dialect, translated by Hans and Ruth Bietenhard, 1990)
D Psalme bärndütsch (Psalms in Bernese dialect, translated by Hans, Ruth and Benedikt Bietenhard, 1994)
S Nöi Teschtamänt Züritüütsch (Zurich German New Testament, translated by Emil Weber, 1997)
D Psalme Züritüütsch (Psalms in Zurich German, translated by Josua Boesch, 1990)
Der guet Bricht us der Bible uf Baselbieterdütsch (parts of the Old and the New Testament in Basel dialect, 1981)
S Markus Evangelium Luzärntüütsch (Gospel of Mark in Lucerne dialect, translated by Walter Haas, 1988)
Markusevangeeli Obwaldnerdytsch (Gospel of Mark in the dialect of the Obwalden County, translated by Karl Imfeld, 1979)
See also
Swiss Standard German
Argentinien-schwyzertütsch dialect
Swiss French
Swiss Italian
Linguistic geography of Switzerland
Notes

Bibliography
Albert Bachmann (ed.), Beiträge zur schweizerdeutschen Grammatik (BSG), 20 vols., Frauenfeld: Huber, 1919–1941.

Rudolf Hotzenköcherle (ed.), Beiträge zur schweizerdeutschen Mundartforschung (BSM), 24 vols., Frauenfeld: Huber, 1949–1982.
Peter von Matt, Deutsch in der Deutschen Schweiz. In: Peter von Matt: Das Kalb vor der Gotthardpost. Zur Literatur und Politik in der Schweiz. München: Carl Hanser, 2012, ISBN978-3-446-23880-0, S. 127–138.
Verein für das Schweizerdeutsche Wörterbuch (ed.), Schweizerisches Idiotikon: Wörterbuch der schweizerdeutschen Sprache. Frauenfeld: Huber, 17 vols. (16 complete), 1881–, ISBN978-3-7193-0413-3.
A Select Bibliography of English Texts on Swiss German offers the  of Schweizerisches Idiotikon.

 – choose the Swiss German words you would normally use and see how well this matches the dialect of your area. (German only)
 a site with sound samples from different dialects. (German only)
 The homepage of the Swiss national dictionary.