"These results indicate that fatalities due to mass shootings were lower during both the federal and state assault weapons ban periods. Although some prior research has shown either that assault weapons bans did not reduce crime or that they actually increased gun-related murder rates, the present study’s focus on mass shootings shows the effectiveness of these gun control measures in reducing murders due to mass shootings. Regarding the injury regression, state-level assault weapons bans had no statistically-significant effects, but the federal ban had a significant and negative effect on mass shooting injuries....the present study’s focus on mass shootings shows the effectiveness of these gun control measures in reducing murders due to mass shootings...In 2012, for example, there were 72 fatalities due to mass public shootings. Of those 72, at least 30 were committed using a rifle. In the same year, there were 12,765 murders, of which only 322 were committed using a rifle. Rifles (assault weapons) are used much more frequently in mass shootings than they are in murders in general. Hence, any law that restricts access to rifles is likely to be much more effective in reducing mass shootings than it is in reducing murders in general."
January 1, 1970
https://en.wikiquote.org/wiki/Assault_rifle