Supreme Court Justice Stephen Breyer, a dissenter to the ruling that struck down Washington, D.C.’s handgun ban, noted that studies on whether gun control laws do any good lack a definitive overall conclusion. Over the five years ending in 1997, there was an average of 36,000 firearms-related deaths a year. (Fifty-one percent were suicides, and 44 percent homicides.) Determining whether particular gun control laws would have prevented some of those deaths is difficult, says the New York Times.
Gary Kleck, a professor at Florida State University's College of Criminology and Criminal Justice, whose work Breyer cited, said, “We know the D.C. handgun ban didn't reduce homicide.” A 1991 study in The New England Journal of Medicine compared Washington to its suburbs before and after the gun law took effect. It found that the law was linked to a 25 percent drop in homicides involving firearms and a 23 percent drop in such suicides. Kleck criticized the study, saying that the period it studied was too short and that the suburbs were a poor point of reference. Kleck compared Washington to nearby Baltimore, which did not have a similar handgun law, yet its crime rate mimicked Washington's. “The law itself had no effect one way or the other,” Kleck said.
Link: http://www.nytimes.com/2008/06/29/weekinreview/29liptak.html?scp=1&sq=liptak&st=nyt