A writer at Breitbart has referenced a study done by Harvard in 2007 debunking the claim that banning firearms would reduce murder or even suicide.
Suicide is the far and away leader in handgun deaths while rifles, including the confusingly-termed 'assault' kind, are barely a blip in murders or suicides, a few hundred per year.
This sort of analysis has been done multiple times and get done each time a shooting tragedy happens. When 'shooting sprees' were blamed on American gun culture last year, it was quickly noted that the rate of shooting sprees in countries where guns are outlawed are not lower.
And that goes for 'intentional deaths' that are not shooting sprees also - like murder and suicide. Finland showed a rate of of gun ownership of 39,000 per 100,000 inhabitants but the murder rate was almost nothing, at 1.98 per 100,000. The murder rate in Russia, where handguns are banned, was 30.6. The rate in the U.S. was 7.8 and that would be even lower today.
And banning guns does not even reduce crime; England, Scotland and Wales hold the top three spots in the developed world for crime, despite banning guns. Banning guns simply means people are far more likely to be assaulted in their homes than Americans are.
So would banning firearms reduce murder and suicide? It's the wrong question and so, like a bad numerical model that gives you a 5-sigma result that is completely incorrect, we get the wrong answer.
AWR Hawkins notes, "In fact, the numbers presented in the Harvard study support the contention that among the nations studied, those with more gun control tend toward higher death rates."
Citation: Don B. Kates and Gary Mauser, 'Would Banning Firearms Reduce Murder and Suicide? A Review of International and Some Domestic Evidence', Harvard Journal of Law & Public Policy, Volume 30, Number 2 – Spring 2007