Among the 11 deadliest shootings in U.S. history, more than half took place in the last five years.
During the same period, states have often relaxed their gun laws, making it easier for individuals to obtain guns, extending the places where concealed guns are permitted, or giving gun owners more robust protections.
We take a closer look at some of the more striking measures:
1. Five states allow students to carry concealed guns on college campuses