I used to be in favour of gun control. My belief was that gun control legislation would cut down on violent crime. Then I started reading various articles that actually studied the evidence. I slowly and reluctantly changed my mind. Here is one of many good articles that summarize the literature (h/t Ted Frank). Some relevant quotes:
Put away your feelings and beliefs. Just ask yourself (and the various articles you read), what policy is likely to lead to fewer mass killings of children and adults in the future? I'm reluctantly coming to the view that gun control leads to more, not fewer, mass killings.
Mass shootings are no more common than they have been in past decades, despite the impression given by the media.
In fact, the high point for mass killings in the U.S. was 1929, according to criminologist Grant Duwe of the Minnesota Department of Corrections.
Incidents of mass murder in the U.S. declined from 42 in the 1990s to 26 in the first decade of this century.
Until the Newtown horror, the three worst K–12 school shootings ever had taken place in either Britain or Germany.
Gun-free zones have been the most popular response to previous mass killings. But many law-enforcement officials say they are actually counterproductive. “Guns are already banned in schools. That is why the shootings happen in schools. A school is a ‘helpless-victim zone,’” says Richard Mack, a former Arizona sheriff. “Preventing any adult at a school from having access to a firearm eliminates any chance the killer can be stopped in time to prevent a rampage,” Jim Kouri, the public-information officer of the National Association of Chiefs of Police, told me earlier this year at the time of the Aurora, Colo., Batman-movie shooting. Indeed, there have been many instances — from the high-school shooting by Luke Woodham in Mississippi, to the New Life Church shooting in Colorado Springs, Colo. — where a killer has been stopped after someone got a gun from a parked car or elsewhere and confronted the shooter.
Economists John Lott and William Landes conducted a groundbreaking study in 1999, and found that a common theme of mass shootings is that they occur in places where guns are banned and killers know everyone will be unarmed, such as shopping malls and schools.