After several attempts over several years, in 2011, Pennsylvania altered its self-defense laws, expanding the Commonwealth’s existing castle doctrine. The changes removed crime victims’ duty to retreat under certain circumstances, changed certain evidentiary standards related to the use of force, and narrowed the rights of violent attackers to bring civil suits. The changes were hotly opposed by traditional anti-gun constituencies who argued volubly and extensively that the changes would increase violence across the Commonwealth. Data gathered in the wake of the changes show that no such wave of violence emerged and that, in fact, violent crime dropped after the expansion of Pennsylvania’s castle doctrine.