Association for Public Policy Analysis & Management

In 2006 California implemented the Armed and Prohibited Persons System (APPS), a monitoring program that identifies known firearm owners who become prohibited from owning a firearm and then subsequently attempts to retrieve all prohibited weapons from such individuals. Through this program, state law enforcement has made hundreds of thousands of contacts with prohibited individuals and has removed tens of thousands of firearms from their possession, sometimes temporarily when the prohibiting condition has an expiration date, but often permanently. We apply synthetic cohort analysis to test for a relative decline in homicide rates in California coinciding with the implementation. We probe the robustness of the analysis exploring several falsification checks involving non-homicide offenses, and homicide where a firearm is not involved.