Dear Science: Can anything be done near term to reduce gun homicides in this country? – Buck R.
Dear Buck: To what extent culture, law enforcement, the pervasiveness of gun ownership, mental illness, education and poverty affect the incidence of gun homicides in the US is largely unknown. In the absence of such knowledge, misunderstandings about what policies might be effective grow like weeds.
Here are four such misunderstandings and what the best data we have say about them.
Misunderstanding 1: Gun homicides are a big problem throughout the U.S.
Let’s put the problem in perspective by comparing it to the incidence of death by other causes. If you are under age 50, on average it is about 100 times more likely that you will die in an auto accident, and 100 times more likely that you will die of a heart attack, than it is that you will be a victim of gun homicide.
If you are 75 or older, on average the chances you will die of a heart attack are about 1,000 times greater than the chance you will be a victim of gun homicide. None of these are desirable ways to die, but these numbers tell us that even if we were to eliminate gun usage in the U.S., it would have no practical effect on our individual chances of survival, on average.
Averages can say less than they seem to, however. If you are a poor non-white male between the ages of 15 and 35 and live in certain parts of Detroit, Washington DC, Chicago, Houston, or Los Angeles, your chances of being a victim of a gun homicide are about 10 times greater than your chances of dying of a heart attack or dying in an auto accident. If you are in that group, gun homicides obviously are a big problem.
Misunderstanding 2: Banning semiautomatic rifles, such as the AR-15 used in the Newtown massacre, will significantly reduce the incidence of gun homicides in the U.S. Unfortunately, all the data we have suggest that banning semiautomatic rifles would have a relatively small effect on the incidence of gun homicides. A study commissioned by the US Department of Justice (see below) showed that even in the absence of a semiautomatic assault-rifle ban in the U.S., such weapons were responsible for less than 10 percent of gun homicide deaths. Given these data, eliminating semi-automatic assault rifles might make us feel safer, but it would lower the risk of gun homicide deaths by at most 10 percent.
Banning the use of large-capacity (holding 10 or more rounds) magazines (LCMs), assuming 100 percent successful enforcement, might reduce the incidence of gun homicides by up to 20 percent, because LCM handguns are responsible for about 20 percent of deaths in gun homicides.
Misunderstanding 3: Arming school guards and teachers who are not already armed will significantly reduce the incidence of gun homicides. Unfortunately, the data say otherwise. Under the current level of legal gun possession and use in schools, only about one in a thousand gun homicide deaths occurs in a school. Even if we turned all schools that are not already such, into armed fortresses, the data states it would make no practical difference in the incidence of gun homicides in the U.S.
Misunderstanding 4: Further reducing the access of mentally ill people to guns will significantly reduce the incidence of gun homicides. The best data we have suggest that roughly 25 percent of gun homicides in the U.S. are committed by mentally ill people, as “mental illness” is defined in the Diagnostic and Statistical Manual of Mental Disorders (which represents the majority view of U.S. mental health profession today). But we don’t have a well-tested theory that tells us what the relationship between mental illness and gun homicides is. It’s therefore not clear that if we reduced, beyond what we are already doing through current gun permitting laws, the access of mentally ill people to guns, that the reduced access would have a significant effect on gun homicides.
In short, there are many confusions and no easy solutions. To identify policy that could at least halve the incidence of gun homicides, we need a much deeper understanding of the root causes of gun homicides. Achieving that understanding, and implementing policies based on that understanding, will take time and money, and, no doubt, changes to public awareness and to law.
For further information, see Christopher S. Koper, Daniel J. Woods, and Jeffrey A. Roth,
An Updated Assessment of the Federal Assault Weapons Ban: Impacts on Gun Markets and Gun Violence, 1994-2003, June 2004 (http://www.sas.upenn.edu/jerrylee/research/aw_final2004.pdf).
Jack Horner is a systems engineer.