Multiple Victim Public Shootings
The only policy factor to have a consistently significant influence on multiple victim public shootings is the passage of concealed handgun laws, conclude John Lott Jr. and William Landes in this National Bureau of Economic Research study using decades of U.S. data. Arrest or conviction rates and the death penalty reduce "normal" murder rates, but public shootings are more sensitive than other violent crimes to concealed handguns, they explain. This debunks the thought that because multiple-victim shooters are often mentally ill, they do not respond to costs and benefits. The concealed-carry effect seems to have a greater ability to stop mass shootings because when more people are allowed to carry guns, more will have them available to defend the public places where these attacks occur.