Recent Firearms Research

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Recent Firearms Research

Internet article

By: David Hemenway

Date: December 19, 2005


About the Author: Dr. David Hemenway is the director of the Harvard Injury Control Research Center upon whose website the review below was published. His research in the area of injury prevention has covered motor vehicle injury, falls, fractures, suicide and child abuse. He is currently looking at gun injuries and related issues, such as firearm storage practices, the costs and benefits of gun ownership and the relationship between the number of guns and gun-related homicide, suicide and accidental death.


Guns—or firearms—can be used legitimately and safely in sport, assuming the owner knows how to look after and use the weapon. But illegal or careless use of guns is the leading cause of homicide and suicide in the U.S. and a significant cause of accidental death too, claiming around eighty lives each day. Many more suffer lasting pain and disability from gunshot wounds. Gunfights seen in the movies and on TV rarely reflect the reality of the damage such powerful weapons can inflict upon the human body.

The nature and severity of a gunshot wound depends upon the type of gun and bullet used, how far away it was fired from and where it enters the body. A bullet is a high speed projectile and when it lands in the body it gives up its kinetic energy. A penetrating gunshot wound is one which enters the body but does not leave it—so there is no exit wound and the bullet is found in the body, possibly at some distance from the place where it entered. A perforating wound enters the body, travels through it and then exits, leaving an exit wound. During its path through the body, the bullet may ricochet—or bounce off—bone like the skull or ribs, which may deflect it from entering the brain or heart.

The damage caused by a gunshot wound occurs because it creates a temporary cavity along its path which then collapses, creating a resultant shock wave which passes through the surrounding tissue. The damage caused depends upon which organ or tissues are affected but, in general, a slow bullet will cause an area of damage that is about three times its diameter. For a high speed bullet, which has greater kinetic energy, the damage extends to ten or more times its diameter. Should the bullet hit the brain, heart or spinal cord, then death may be more or less spontaneous because of the sudden loss of vital functions. If it hits elsewhere then death, if it occurs, will be by exsanguination (bleeding to death) or by infection of the wound inflicted, which is common in war situations. The extract below looks at some of the risk factors contributing to the high rate of gunshot wounds in the USA, which could form the basis of policy for reducing the high death and disability toll from gun violence.



Guns and homicide (literature review).

We performed a review of the academic literature on the effects of gun availability on homicide rates.

Major Findings: A broad array of evidence indicates that gun availability is a risk factor for homicide, both in the Untied States and across high income countries. Case-control studies, ecological time-series and cross-sectional studies indicate that in homes, cities, states and regions in the US, where there are more guns, both men and women are at higher risk for homicide, particularly firearm homicides.

Publication: Hepburn, Lisa; Hemenway, David. "Firearm Availability and Homicide: A Review of the Literature." Aggression and Violent Behavior: A Review Journal. 2004; 9:417-440.

Gun availability and suicide in the Northeast

We analyzed data on suicide and suicide attempts for states in the Northeast.

Major Findings: Even after controlling for rates of attempted suicide, states with more guns had higher rates of suicide. Case fatality rates ranged from over ninety percent for firearms to under five percent for drug overdoses, cutting and piercing (the most common methods of attempted suicide). Hospital workers rarely see the type of suicide (firearm suicide) that is most likely to end in death.

Publication: Miller, Matthew; Hemenway, David; Azrael, Deborah. "Firearms and Suicide in the Northeast" Journal of Trauma. in press.

Publication: Miller, Matthew; Azrael, Deborah; Hemenway, David. "The Epidemiology of Case Fatality Rates for Suicide in the Northeast." Annals of Emergency Medicine. 2004; 723-30.

Gun availability and suicide in the US

Using survey data on rates of household gun ownership levels across states and years, in a cross-sectional analysis we used data for 1999–2001 for all states, and in a time-series analysis, we used national data for 1981–2001.

Major Findings: States with higher levels of household gun ownership had higher rates of firearm suicide and overall suicide. This relationship held for both genders and all age groups. It remained true after accounting for poverty, urbanization and unemployment. There was no association between gun prevalence and non-firearm suicide. Longitudinally, at the same time that fewer households contained guns, the firearm suicide and overall suicide rate fell. There was no evidence of method substitution.

Gun versus non-gun suicide by children

We analyzed data from the Arizona Childhood Fatality Review Team comparing youth gun suicide with suicide by other means.

Major Findings: Children who use a firearm to commit suicide had fewer identifiable risk factors for suicide, such as expressing suicidal thoughts. Gun suicides appear more impulsive and spontaneous than suicide by other means.

Publication: Azrael, Deborah; Hemenway, David; Miler, Matthew; Barber, Catherine; Schackner, Robert. "Youth Suicide: Insights from five Years of Arizona Child Review Team Data." Suicide and Life Threatening Behavior. 2004; 34:36-43.

Firearm storage and unintentional firearm death across U.S. states

We analyzed data from the 2002 Behavioral Risk Factor Surveillance System which asked questions about guns and gun storage in the home, combined with information on deaths from the National Center for Health Statistics.

Major Findings: Both Firearm prevalence and questionable storage practices (I.e. storing firearms loaded and unlocked) were associated with higher rates of unintentional firearm deaths.

Submission: Miller, Matthews; Azrael, Deborah; Hemenway, David; Vriniotis, Mary. "Firearm Storage Practices and Rates of Unintentional Firearm Deaths in the United States." Accident Analysis and prevention. 2005; 37: 661-667.

Murder followed by suicide in Kentucky.

We analyzed data from the Kentucky Firearms Injury Statistics Program for 1998–2000.

Major findings: While less than seven percent of all firearm homicides were followed by a firearm suicide, in two-thirds of the cases in which a woman was shot in an intimate partner-related homicide, the male perpetrator then killed himself with the firearm. Few of these female victims had contact with the Department of Community-based Services.

Publication: Walsh, Sabrina; Hemenway, David. "Intimate partner Violence: Homicides followed by Suicides in Kentucky." Journal of the Kentucky medical Association. 2005 Jan;103(1):10-3.


Guns threats against, self-defense gun use by adolescents

We analyzed data from a telephone survey of 5,800 California adolescents aged twelve to seventeen, which asked questions about gun threats against, and self-defense gun use by these young people.

Major Findings: These young people were far more likely to be threatened with a gun than to use a gun in self-defense, and most of the reported self-defense gun uses were hostile interactions between armed adolescents. Males, smokers, binge drinkers, those who threatened others and whose parents were less likely to know their whereabouts were more likely both to be threatened with a gun and to use a gun in self-defense.

Publication: Hemenway, David; Miller, Matthew. "Gun Threats Against and Self-Defense Gun Use by California Adolescents." Archives of pediatrics and Adolescent Medicine. 2004; 158:395-400.

Batterers' use of guns

We conducted a survey and analyzed data collected from over eight thousand males enrolled in a certified batterer intervention program in Massachusetts, 1999–2003.

Major Findings: Recent gun owners were eight times more likely to have threatened their partners with a gun than non-gun owners. Four main types of gun threat against partners were (a) threatening to shoot then, (b) threatening to shoot a pet or person the victim cares about, (c) cleaning, holding or loading a gun during an argument, and (d) shooting a gun during an argument.

Submission: Rothman, Emily; Hermenway, David; Miller, Matthews; Azrael, Deborah. "Batterers' Use of Guns to Threaten Intimate Partners" Journal of the American Medical Women's Association. 2005, 60:62-68.


Unsupervised firearm handling by adolescents

We analyzed data from a telephone survey of over 5,800 California adolescents conducted in 2000–01.

Major Findings: One-third of adolescents reported handling a firearm, 5% without adult supervision or knowledge. Smoking, drinking and parents not knowing the child's whereabouts in the afternoon were associated with unsupervised gun handling. These events usually occur away from home, with friends. Half involve shooting the gun.

Publication: Miller, Matthew; Hemenway, David. "Unsupervised Firearm Handling by California Adolescents." Injury Prevention. 2004; 10:163-68.

Concealed carrying by adolescents

We analyzed data from over 1,800 youth in Chicago.

Major findings: Aspects of the neighborhood (social disorder, safety, collective efficacy) were important predictors of illegal gun carrying by youth.

Publication: Molnar, Beth; Miller, Matthew; Azrael, Deborah; Buka Steven. Neighborhood predictors of concealed firearm carrying among children and adolescents: results from the project on human development in Chicago neighborhoods. Archives of Pediatric Adolescent Medicine. 2004; 158:657-64.


Public health approach

This chapter summarizes the public health problems caused by firearms, and the public health approach to reducing firearm injuries.

Publication: Hemenway, David. "A Public Health Approach to Firearms Policy" in Mechanic, D. Policy Chal-lenges in Modern Health Care. New Brunswick, NJ: Rutgers University Press, 2005.

Effect on homicide of gun carrying laws

We analyzed the effect on homicide of changes in state-level gun carrying laws using pooled cross-sectional time-series data for fifty states from 1979–1998.

Major Findings: There was no statistically significant association between changes in concealed carry laws and state homicide rates. The finding was consistent across a variety of models.

Publication: Hepburn, Lisa; Miller, Matthew; Azrael, Deborah; Hemenway, David. "The Effect of Nondiscretionary Concealed Weapon Carrying Laws on Homicide." Journal of Trauma. 2004; 56:676-681.

Effect of child access prevention laws on unintentional child firearms fatalities

We analyzed the effect on unintentional firearm fatalities to children of child access prevention (CAP) laws, which allow a firearm owner to be charged with a crime if a child gains access to an unsecured firearm, using pooled cross-sectional time series data for fifty states from 1979–2000.

Major findings: States that enacted CAP laws—with felony rather than misdemeanor penalties—experienced great subsequent declines in the rate of unintentional firearms deaths for children from birth to fourteen compared to states not enacting CAP laws.

Submission: Hepburn, Lisa; Azrael, Deborah; Miller, Matthew; Hemenway, David. The effect of child access prevention laws on unintentional child firearm fatalities, 1979–2000.


Measures of firearm prevalence

Various proxy measures for the prevalence of firearm ownership were compared with surveys-based estimates.

Major Findings: One proxy, the percentage of suicides with a firearm, performed consistently better than other measures in cross-sectional comparisons.

Publication: Azrael D, Cook PJ, Miller M. State and local prevalence of firearms ownership: Measurement, structure and trends. Journal of Quantitative Criminology. 2004; 20:43-62. See also National Bureau of Economic Research Working Paper #8570.


Gunshot wounds are not only an issue in the U.S. Around the world, 300,000 people a year die from gunshot wounds and a million more suffer disabling injuries. The ensuing cost to the health services is significant. In the U.S., the medical cost per injury is said to be 17,000 dollars and in Canada, gunshot wounds cost the nation five billion dollars a year. There are indirect public health effects of guns too—they play a role in conflict in many countries, leading to migration of the population, disruption of their infrastructure and the spread of infection. Sexual violence at gunpoint poses an increased risk of HIV/AIDS and other sexually transmitted infections.

Gun violence, then, can be seen as a public health problem. As with many other public health problems, there are various approaches to control. One way is the so-called zero tolerance approach which has been tried with smoking, drugs and HIV infection. If guns were banned, the argument goes, there would be no gun violence, just as sexual abstinence could eliminate the spread of HIV. However, many people believe they have the right to own a gun—either for sport or to use in self-defense. Another way might be to try to control the circulation of guns used deliberately to harm people by requiring owners to register their weapons. This is perhaps similar to trying to control the sale of tobacco and restrict its use. Many studies, such as the ones described in the extract above, have shown that gun availability is indeed a risk factor for homicide. This would seem to present a good argument for restricting the sale of guns, in the interests of the population at large. The way in which this might be done, however, is open for debate. There is also a case for more training for gun owners so that weapons do not pose a risk of accident, nor do they find their way into the wrong hands. It is also important to consider the reduction of gun violence in the context of reducing all kinds of violence, whether against others or against oneself. If gun use is restricted, people may turn to other means of suicide, showing that what is also needed is a strategy to tackle depression and other mental health problems.



James, Stuart H., and Jon J. Nordby. Forensic Science. Boca Raton, FL, CRC Press, 2003

Lyle, Douglas. Forensics for Dummies, Hoboken, N.J., Wiley, 2004

Web sites

International Action Network on Small Arms. "The Public Health Approach to Preventing Gun Violence." 〈〉 (accessed March 27, 2006)