Current gun purchase laws are not strong enough to tackle gun crime.
Every day, guns kill over 90 people in the US. In 2010, there were 31,672 recorded gun deaths, equivalent to 10.1 per 100,000 people.
Hawaii has the lowest rate, with 45 fatalities in 2010, equivalent to 3.31 per 100,000 people. Alaska saw 144 deaths or 20.3 per 100,000, the highest rate in the country.
Young adults aged 17-25 years are most likely to be involved. Firearms feature in 80% of all homicides and 45% of all suicides for this age group.
Currently, only nine of the 25 state laws appear to be effective in reducing the number of deaths from gun use.
The policies most likely to reduce gun deaths are those requiring background checks for purchasing guns and ammunition, and the stipulation that firearm owners should carry identification.
There is evidence that the more people own guns, the more gun deaths occur, but precisely how effective existing gun laws are is not clear.
No background checks in at least 40% of all sales
The main federal gun control law is the Brady Law, which states the need for background checks for people buying guns from a federally licensed dealer.
However, private transactions, which account for 40% of all gun sales, do not require such checks. In addition, states across the US have implemented a range of gun laws that either strengthen or deregulate the Brady Law.
Dr. Kalesan and colleagues from Boston University in Massachusetts wanted to investigate the link between gun-control laws and recorded gun deaths across the US, and to calculate which laws might affect the number of such fatalities, based on figures from 2008-2010.
The team looked at rates of gun death, injury statistics from the Centers for Disease Control and Prevention (CDC), 25 different gun-control laws, rates of gun ownership, gun export, non-firearm homicides and unemployment.
Findings show that nine of the laws potentially prevent a number of gun deaths, nine increase the risk and seven make no difference.
Self-defense laws increase the chance of gun deaths
Laws demanding locks and age restrictions, which would limit firearm access to children, appear to be ineffective. In contrast, legislation permitting individuals to use deadly force to defend themselves implies a significantly higher rate of gun-related deaths, even after adjusting for factors such as unemployment and gun exports.
Results suggest that a federal law expanding background checks for all gun purchases could reduce the national rate of gun deaths by 57%, from 10.35 to 4.46 per 100,000 people.
Background checks for all ammunition purchases could mean an 81% decrease in fatalities, down to 1.99 per 100,000. Firearm identification could bring about a drop of 83%, to 1.81 per 100,000.
Federal implementation of all three laws could, in the long term, decrease the number of gun deaths nationwide by over 90%, to 0.16 per 100,000. However, it could take several years to see the benefits.
The researchers say this is the first study into the impact of specific gun laws on gun-related deaths, and how they are affected by other factors, including gun ownership and unemployment.
Lead author Dr. Kalesan says:
"The findings suggest that very few of the existing state gun-control laws actually reduce gun deaths, highlighting the importance of focusing on relevant and effective gun legislation. Background checks for all people buying guns and ammunition, including private sales, are the most effective laws we have to reduce the number of gun deaths in the USA."
In a linked comment, Prof. David Hemenway, of Harvard School of Public Health in Boston, MA, points out the need to factor in issues such as poverty, alcohol consumption, urban lifestyle and mental health. He cautions that the 90% figure is too optimistic.
Nevertheless, he calls the study "a step in the right direction," toward gathering scientific evidence that can address "the serious gun-violence problem" in the US.
Medical News Today reported last year that around 9% of adults with firearms in the US have anger management problems.