Similarly, Illinois had a background check requirement before 1994, so the local gun market was not affected by the passage of the Brady Act, but gun trace data shows that criminals simply switched from smuggling guns from out of state to buying them illegally in state.
(More: Where 50,000 Guns Recovered in Chicago Came From, New York Times)
How often are guns used in self-defense?
There are no comprehensive records kept of incidents where guns are used in self-defense, so the only way to know is to ask people. Data from the National Crime Victimization Survey suggest that a gun is used in self-defense about 60,000 to 120,000 times each year. Several other surveys confirm this estimate. By comparison, each year about a million violent crimes involve guns. This means guns are used to commit a crime about 10 times as often as they are used for self-defense.
A few surveys in the early 1990s suggested that there are millions gun self-defense incidents each year, but there are very good reasons to believe that these estimates were improperly calculated and these numbers are way off, more than 10 times too high. If the numbers really were this high, this would imply that pretty much every gunshot wound in America is the result of somebody protecting him or herself.
Even among the more accurate surveys, according to a panel of criminal court judges who reviewed survey respondents' stories, about half the time the gun use was "probably illegal," even assuming the gun itself had been purchased legally.
(More: Gun threats and self-defense gun use, Harvard Injury Control Research Center)
Won't criminals kill with other weapons if they don't have guns?
The crux of this question is whether most homicides are planned, or whether killers more often confront their victims with no clear intention. In the second case, adding a gun could result in a fatal shooting that would otherwise have been avoided.
The evidence that weapon does matter goes back decades. In 1968, Franklin Zimring examined cases of knife assaults versus gun assaults in Chicago. The gun attacks were five times more deadly. Moreover, the two sets of attacks were similar in all other dimensions: age, sex, race, whether the victim knew the assailant beforehand, and so forth. A few years later, he repeated his analysis, this time comparing small and large caliber guns. As expected, the victim was much more likely to die from larger caliber guns.
Although it is surely true that a determined killer cannot be stopped by the absence of a gun, this type of evidence indicates that many homicides are unplanned. The outcome depends, at least partially, on the weapon at hand. In that restricted sense, guns do kill people.
(More:Crime is Not the Problem: Lethal Violence in America, by Franklin E. Zimring and Gordon Hawkins)
What has worked to reduce gun violence?
This is not an easy question to answer, because crime rates can decline for a wide range of reasons. For example, violent crime rates declined sharply all across the country in the mid-1990s, regardless of whether a given area had tightened its gun laws. So based on a naive interpretation of the numbers, any attempt at reducing gun violence in 1995 would have appeared successful by 1998. Then there is the problem of comparing different states or cities: Circumstances differ, and what works in Memphis may fail in Detroit.
Nonetheless, there are some plausible methods for isolating the different factors, using comparison groups or other controls. The most thorough summary is a 2008 meta-analysis where the authors reviewed every prior American gun violence reduction study, examining both the reported effectiveness and the strength of the statistical evidence. Here are some approaches that don't seem to work, at least not by themselves, or in the ways they've been tried so far:
- Stiffer prison sentences for gun crimes.
- Gun buy-backs: In a country with one gun per person, getting a few thousand guns off the street in each city may not mean very much.
- Safe storage laws and public safety campaigns.
We don't really have good enough evidence to evaluate these strategies:
- Background checks, such as the Brady Act requires.
- Bans on specific weapons types, such as the expired 1994 assault weapons ban or the handgun bans in various cities.
These policies do actually seem to reduce gun violence, at least somewhat or in some cases:
- More intensive probation strategies: increased contact with police, probation officers and social workers.
- Changes in policing strategies, such increased patrols in hot spots.
- Programs featuring cooperation between law enforcement, community leaders, and researchers, such as Project Safe Neighborhoods.
There is no obvious solution here, and there's a huge amount we still don't know. But it's possible that combinations of these policies, or variations in a different context, might work better. For example, background checks would probably be more effective if they were also applied to private sales. Also, of course, this list does not include policies that have not yet been tried.
There are no feasible policies that would reduce the rate of gun violence in the United States to that of Western Europe. But we believe there are ways to make a substantial dent in the problem.
(More: The Effectiveness of Policies and Programs That Attempt to Reduce Firearm Violence: A Meta-Analysis, Journalist's Resource. Project Safe Neighborhoods and Violent Crime Trends in US Cities: Assessing Violent Crime Impact, Edmund F. McGarrell, Nicholas Corsaro, Natalie Kroovand Hipple, Timothy S. Bynum)