With vast developments of science and technology today, more and more criminal investigations are relying on scientific methodologies in solving cases. DNA testing has been a revolutionary mechanism in the criminal justice system. Traditionally, the identification of a person required the observation of that person’s entire body or localized special characteristics such as fingerprints, blood group or hair type. In comparison, DNA analysis allows identification by reference to the information contained in any human nucleic cell, irrespective of which part of the body the cell comes from.1 It provides scientific proof of numerous innocent people have been convicted and sentenced under the current system. This shows that the current criminal justice system is fundamentally flawed. Innocent men who were convicted had lost their time, dignity and suffered from incalculable damages. The ones who have been wrongly put on the death row have even lost their lives for crimes they have not committed. As a result, organizations, experts and government officials from all over the world have come to the same conclusion— a reform in our criminal justice system regarding DNA evidence is necessary. Yet, criticisms against DNA evidence were raised; pinpointing DNA evidence is not perfect.
Some jurisdictions have established formal independent review bodies to investigate suspected wrongful convictions, and, if necessary, to refer them to courts for consideration for appeals. An example is the Criminal Case Review Commission in UK. In the United States, the National Commission on the Future of DNA Evidence was established by the Department of Justice to “maximize the value of DNA in our criminal justice system”2 While the finality in the criminal justice system is respected, the commission strongly encourages the pursuit of truth. It was suggested that the claims of actual innocence should be valued over mechanical obedience to time limits on appeals, or other procedural and institutional restrictions to justice. In Canada, a commission was established to review the general effects of DNA evidence on the administration of justice after a Toronto man convicted of murdering a nine year-old girl in 1984 was acquitted of the charge based on new DNA evidence that showed he could not have committed the crime.3 After months of hearings, extensive recommendations for reforming the Canadian criminal justice system in light of the DNA revolution has been made.
The panel put together by the U.S. DOJ has also produced a guideline regarding recommendations for eyewitness evidence.4 This is because in the absence of DNA evidence at the trial, eyewitness testimony was the most compelling evidence. Unmistakably, however, the recent exonerations prove many of those eyewitness testimonies were wrong. Thus the reliability of eyewitness testimony has been criticized extensively. Experts have commented that a major problem is the vulnerability of eyewitnesses to suggestions from the police officers, whether intentional or unintentional. In the report it was stated that “pressure that comes from the police who want to see the crime solved, but there is also a psychological pressure that is understandable on the part of the victim who wants to see the bad guy caught and wants to feel that justice is done.”5 Some of the recommendations for eyewitness testimonies include interviewing a witness with open-ended questions and avoiding questions that would lead the witness, which is practically the principles of today, even in Hong Kong. It was said that open-ended questions can elicit much more information, but the police tend to ask few open-ended questions and to interrupt witness who try to give narrative answers. In contrast, researchers have found that leading questions can change what the witnesses have to say. It was also suggested to have only one suspect at a time be in an identification parade and ensuring that fillers to be people who fit the general description the witness has given. Studies have concluded that identification parades with more than one suspect increase the chance of a mistaken identification. Moreover, if fillers in the identification parade do not match the general description, the witness is likely to pick the suspect if he looks most like that description. Another suggestion included in the report is to tell the witness that the perpetrator may not be in the line-up. This is because sometimes the witnesses feel like it is their job to pick the person who looks like the perpetrator the most.6 These three are the most recognized and adopted principles even by other jurisdictions regarding eyewitness evidence.
In Hong Kong, DNA analysis has been regarded as an even more effective forensic device after the Police Force Ordinance took effect in 2001. The Police are given powers by the legislation to take DNA samples from suspects, persons convicted for serious arrestable offences and volunteers for identification purposes.7 The serious arrestable offences are defined as those for which a person may under or by virtue of any law be sentenced to imprisonment for not less than five years.8 It later included all dangerous drugs offences, firearms and ammunition offences and most of the offences under the Prevention of Child Pornography Ordinance. While in UK, the threshold for taking DNA profiles is any recordable offence irrespective of the level of punishment. In Canada, the threshold is all those offences involving violence and sexual assault. In Australia, it is any criminal offence irrespective of the level of punishment. The Hong Kong legislation provides that only trained officers can take non-intimate DNA samples from persons. Whereas swabs from people’s mouths are done by certified frontline police officers that have been trained by Government Laboratory, the task of finding DNA samples at crime scenes are done by veteran Scene of Crime Officers from Identification Bureau.9 There is also the voluntary system which allows a convicted offender to volunteer for giving a non-intimate sample and have his DNA information stored until the time his innocence is proved and/or his authorization is withdrawn. Regarding the protection of privacy of the owner of the DNA, Hong Kong’s officers will seal it and attach a barcode label before taking it to the Government Laboratory for testing and the sample has to remain anonymous. Names, identity card numbers or other personal particulars and the corresponding barcode numbers will be kept in strict confidentiality by the Police’s Criminal Records Bureau. The chemists also have no access to such information. Section 59G(2) further provides that no person shall have access, to disclose or use any of the information stored in the DNA database unless for the purpose of “i) forensic comparison with any other DNA information in the course of an investigation of any offence by a police officer or an officer of the Independent Commission Against Corruption; (ii) producing evidence in respect of the DNA information in any proceedings for any such offence; (iii) making the information available to the person to whom the information relates; (iv) administering the DNA database for the purposes of or connected with any of the following- (A) paragraph (i), (ii) or (iii) or subsection (1); (B) section 59H; or (v) any investigation or inquest into the death of a person under the Coroners Ordinance.”10
Less formal review bodies were also set up by legal academics and defence lawyers were also established to assist convicted persons. One of the most famous groups is The Innocence Project, an American national litigation and public policy organization founded in 1992 that helps exonerate wrongfully convicted individuals through DNA testing in United States.11
DNA evidence has been used in numerous cases all over the world. In Australia, DNA evidence is admissible in criminal trials, subject to the evidentiary requirements that: it is relevant to the facts in issue, is presented in an appropriate manner by qualified witnesses, and that it does not cause unfair prejudice to the accused.12 However, unlike the United States, Australia has not featured DNA identification in the post-conviction detection of such errors by Australian appeal courts.13 Button, in which the Queensland Court of Appeal unanimously accepted that a DNA test conducted after a rape conviction indicated that someone other than the appellant had committed the offence, was a remarkable exception.14 Button was the first Australian appeal overturning a conviction on the basis that DNA evidence not presented at trial but considered on appeal. Although the Courts of Criminal Appeal are statutorily empowered to receive evidence if it is deemed “necessary or expedient in the interests of justice”, there is a common law requirement that the evidence must be “cogent” and “fresh”.15 As a result the High Court of Australia has no power to receive fresh evidence in a criminal appeal and therefore unable to hear an appeal based on new DNA evidence. The New South Wales’ government then created the Innocence Panel which other Australian jurisdictions may follow.16
The use of DNA identification in criminal investigations generates a link between a suspect and a crime which ultimately leads to a conviction. It provides a less costly alternative for the less efficient traditional investigative techniques, which can lead investigators to target the wrong person in some cases. A negative result in a DNA comparison may prevent a wrongful conviction, as innocent parties may be removed from suspicion at early stages of an investigation.17 DNA evidence may also affect the behavior of offenders, such as by prompting admissions or incriminating attempts to evade DNA profiling or explain away a profile match.18 With the introduction of DNA identification, some offenders may even be deterred from further criminal activity due to the increased risk of detection.
The agencies that are responsible for carrying out the DNA tests are an important factor. In Hammond, the judge ruled that the DNA evidence was inadmissible on the basis that there was uncertainty as to the quality of the analysis.19 The decision was later upheld by Gordon.20 In this particular case it was suggested that the variation could not be determined on the membrane and that “the database which was used to determine the probability of finding the same single locus profile in the general Afro-Caribbean population was not soundly based.”21 This caused the Home Office to create a larger database for each recognizably different racial group. Nevertheless, techniques of DNA analysis and forensic science have progressed. With developments of technologies, the techniques have, and will, increase the ability of the forensic science community to discriminate between individuals. This further helps restoring justice for those who were wrongly convicted.
In contrast, the increased reliance on DNA technology in criminal investigations has its costs. An obvious one is the financial costs of scientific expertise, laboratory equipment and the administration of information database. Moreover, there is the unquantifiable cost of the use of DNA evidence as a possibility of reducing individual freedoms, particularly the right to privacy. The use of DNA evidence involves invasions of bodily integrity and the study of individual genetic information, some which may be coerced, both lawfully and otherwise.22 Some have criticized that although the infringements of privacy from DNA sampling may be minor, the increased use of DNA evidence by investigators may lead to other more intrusive infringements to become more acceptable.23 An example would be the study of DNA by public and private organizations to detect inheritable characteristics. The investigative power of DNA evidence may also create pressures to cooperate with criminal investigations that undermine the privilege against self-incrimination.24
In addition, some have pointed out the features of DNA evidence that are viewed as its major benefits also give rise to potential dangers. Juries nowadays, who are familiar with forensic science TV shows such as Cold Case, putting the actual figures and the ones of their TV shows together to conclude that guilty is the only reasonable choice.25 This problem arises due to the fact that we lose a number of cells everyday and we leave our DNA everywhere we go. This results in sometimes having our DNA ending up in places we have never been.26 This is the core difference between DNA and fingerprints evidence. Fingerprint identification on a fixed object may establish the fact that a person was at a particular point, but DNA can be transferred from one to another and from there to another place you may have never been. Of course, if there are blood or semen stains that could be seen, we would be more confident that this established a link between the source of the stain and the location of the owner. On the contrary, one may walk through the supermarket and one of the cells somehow got into a vehicle and ended up distance away. Putting these possibilities together, it results in a potential scenario where your DNA is found at a crime scene that you have never been before. Inevitably you become a suspect when your name and address are obtained from the database. Then the juries are informed that there is a match, it is quite possible that they would think of you as a liar when you say you have never been in that location even though that is the truth. Furthermore, this piece of DNA evidence is not likely to be simply placed alongside with some other circumstantial evidence as it appears to be compelling evidence to gain a conviction since almost no one would be able to provide an alibi for every hour of every day. This shows that although DNA evidence can be effective in proving someone innocent, certain coincidences may have DNA evidence leading the juries to reach a wrongful conviction.
Although the current trends are leading us to rely more on DNA evidence, it should not be the ultimate arbiter in conviction. When there is a match one of the questions that arise is: “What is the probability that the defendant is innocent, given that his DNA profile matches the profile from the crime sample?”27 The answer to this question depends on the perception of the defendant’s innocence, which is in itself a subjective test. The results of DNA sample is a solid fact. However, the interpretation is crucial to the correct understanding of what the result means. Depending on what questions are raised, the analysis can be misleading. Such “prosecutor’s fallacy” has become more prominent due to the increased use of DNA evidence.28 Even so, it is up to the court or the jury to decide that the defendant is innocent or not regardless of the DNA result. Deen was the first case to have a conviction based primarily on DNA evidence.29 In that case there was an ambiguity between the probability that the defendant’s DNA matched the crime scene profile and the probability that the defendant was the person who left his DNA at the crime scene. Expert witness has described that the likelihood of the offender being anyone other than the defendant was one in three million. There are two approaches to the probability of a match. One is based on the probability of finding anyone else within a defined population that has the same profile as the defendant (random match probability).30 On the other hand, the one that was used in court was based on the concept of the likelihood that the defendant had committed the crime (likelihood ratio).31 The problem there was that the first calculation was used to answer a question about the likelihood of the defendant’s guilt. This case marks as an example of “prosecutor’s fallacy” where it is based on a misconception of a random match probability is the same as a likelihood ratio (which is not always deliberately created by the prosecution). This is why DNA analysis should be explained clearly in court or else it would not be restoring justice if we are exonerating wrongly convicted individuals and wrongly convicting innocent individuals with the use of DNA evidence at the same time. When DNA evidence was first introduced, the question of “how do statements of probability derived from DNA relate to the traditional concept of reasonable doubt in judgments of innocence and guilt in criminal cases?” was raised.32 In the English case of Doheny & Adams, the court had made a specific recommendation on how the match probability should be presented to the jury to avoid confusion.33 The court held “The scientist should not be asked his opinion on the likelihood that it was the Defendant who left the crime stain, nor when giving evidence should he use terminology which may lead the Jury to believe that he is expressing such an opinion.”34 In addition, the court of appeal has outlined a standard template for the DNA evidence to the juries: “Members of the Jury, if you accept the scientific evidence called by the Crown, this indicates that there are probably only four or five 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.”35 One may say that this situation is ironic because convictions in criminal trials have always been based on the balance of probability in common law jurisdictions and DNA evidence itself is also base on probability, yet, there is still no absolute definition of how much should be enough to convict a person.
There is more to why DNA evidence should not be oversold as an exculpatory tool. DNA identification has its limitations as a crime-solving tool in crimes involving multiple suspects. For instance, in a rape-murder case with multiple-offenders without eyewitnesses, it is possible that only one of the suspects raped or ejaculated in the victim. DNA testing of semen in cases like this would likely to acquit one or more of the suspects. In reality, this type of scenarios combined with other exculpatory evidence such as an alibi and lack of other physical evidence pressures prosecutors to acquit one or more of the suspects.36 As a result, the only other evidence against them that is available would be the testimony of a suspect who matches the crime’s DNA evidence. This situation was illustrated by Dabbs, where the victim claimed that she was dragged into an alley and raped by one man while two other held her down.37 The defendant was convicted through identification by the victim and the other alleged co-offender were never identified or arrested. Later DNA tests showed that the semen evidence from the victim did not match the defendant’s and therefore was exonerated later. In contrast, a theory was raised that the defendant participated in the crime but was not the rapist.38 The prosecutor however ultimately dismissed the original indictment because of the DNA results and the victim’s reluctance to testify at the new trial. This indicates that the practice of panels such as The Innocence Project may sometimes exonerate individuals who were actually guilty of the crime. Yet, at the end of the day, verdicts of criminal trials are based on the balance of probability. One may always argue that when compared to punishing an innocent man, to let a guilty man run free is the lesser of two evils.
It is almost certain that there will be more post-conviction reviews with reliance on DNA evidence. Seeing that we cannot rely on DNA evidence solely to restore justice, there is a need to modify the current system to suit the future reviews. Frederick R. Bieber, an associate professor at Harvard Medical School, and David Lazer, a professor at Harvard’s John F. Kennedy School of Government, commented that the reanalysis of old evidence using new methods should be imbedded within the existing system and not dependent on pleas from the outside and good will from the inside.39 They also suggested with legislatively mandated funding and external oversight, other cases would receive fair and equitable scientific and legal review. In U.S., thirty states have moved towards such legislation. Nevertheless, the existing practice of managing eyewitness testimonies is still considered as the core flaw of the current legal system. More and more jurisdictions are amending their eyewitness evidence or to adopt the guidelines put forth by the U.S. DOJ mentioned earlier in this paper. Another problem is that physical evidence is not well-safeguarded enough. In Maher, access to such evidence was delayed for almost a decade due to misplacement, which the evidence was found later in the basement of a courthouse by a law student who was investigating the case.40 This is not regarded uncommon. The Innocence Project estimates that the key physical evidence is missing in 75 percent of the cases that they work on.41 Therefore the criminal justice system requires more improvement on the storage and inventory of crime-scene evidence.
In the society and justice’s interest, restoring justice should not be limited to mere exoneration. As for post-exonerations, experts have commented that the statutes of time limitations should be amended to convict perpetrators where DNA evidence is newly available.42 This is to allow the same DNA analysis that exonerates the innocent can also use to convict the guilty. In most cases, even the real offenders have been found after innocent men have been exonerated, they cannot be prosecuted due to fact that the statutes of limitation on the assaults has expired. This is said to be the “final injustice” by some critics.43 Furthermore, the victims of wrongful conviction deserve to be compensated. Most of them have lost an irreplaceable period of their lives. Financial compensations and social services should be awarded to facilitate starting over with their new lives.
To conclude, where many have been wrongly convicted, DNA evidence may create the basis for an appeal against the conviction. In many countries, post-conviction DNA testing has been used to overturn wrongful verdicts. Some of the cases even involved prisoners who were awaiting execution for serious crimes. It should be noted that samples for DNA profiling should be as complete and as free from decay and degradation as possible to ensure later tests to be as more accurate. The correct interpretation must also be ensured by the court as there are many complications and issues with DNA evidence. In my opinion, the current system is not perfect and there is room for improvements in many areas.
1 Brownsword Roger, Cornish W.R. & Llewelyn Margaret, Human Genetics and the Law Regulating a Revolution, Hart Publishing Oxford (1998)
2Frontline,“The Case For Innocence” <http://www.pbs.org/wgbh/pages/frontline/shows/case/>, WGBH educational foundation (2000)
3 R. v. Morin,  2 S.C.R. 345
4 Connors Edward, Lundregan Thomas, Miller Neal & McEwen Tom, Convicted by Juries, Exonerated by Science, Research Report by NIJ, U.S. DOJ (1996)
5 ibid, pg. 24
6 supra n.4
7 Police Public Relations Branch, Cracking Crime with DNA Technology, Police Report No.2 2004
8 Legislative Council, Report of the Bills Committee on Dangerous Drugs, Independent Commission Against Corruption and Police Force (Amendment) Bill 1999
9 supra n.7
10 Cap 232 Police Force Ordinance Section 59G
11 Scheck, Neufeld & Dwyer 2000; Innocence Project 2002
12 Gans Jeremy & Urbas Gregor, DNA Identification and the Criminal Justice System, Australian Institute of Criminology (2002)
14 R v Button  QCA 133
15 supra n.12
16 Australian Law Reform Commission & Australian Health Ethics Committee 2001
17 Wall Wilson, Genetics And DNA Technology: Legal Aspects, Cavendish Publishing Limited (2002)
18 Supra. n.12
19 R v Hammond, unrep., 7/12/92, CCA NSW
20 R v Gordon Crim LR 413
22 supra n. 1
24 supra n.11
25 Jamieson Allan, LCN DNA- Devil in the Detail, Journal of the Law Society of Scotland, Sweet & Maxwell Limited, 2007
26 supra n. 16
28 supra n.17
29 R v Deen CA, 21 December 1993
30 Williams Robin, Johnson Paul & Martin Paul, Genetic Information & Crime Investigation, University of Durham (2004)
31 supra n.17
32 supra n. 30
33 R v Doheny & Adams  1 Crim App R 369
36 supra n.4
37 Dabbs 529 N.Y.S.2d 557
38 supra n.4
39 Bieber R. Frederick & Lazer David, Lessons Learned from a Miscarriage of Justice, Boston Globe (2003)
41 supra n.11
42 supra n.39