In the United States, firearms are used to commit homicide more frequently than all other methods combined. According to the US Department of Justice, firearms are used to commit more than 1 million crimes each year. Despite the magnitude of this problem, little is known about the epidemiology of firearm crimes and assaults. Many states require medical personnel to report all nonfatal shootings to law enforcement, but the rate of compliance with this requirement is unknown. To enhance cooperation between community emergency departments and law enforcement agencies, we created a unified firearm injury notification system for the City of Atlanta, Georgia, and 5 surrounding counties: Fulton, DeKalb, Cobb, Gwinnett, and Clayton. Our findings are reported here.