I’ve served in law enforcement nearly my whole career, currently as San Francisco’s district attorney, and before that as chief of police in San Francisco and Mesa, Ariz., and as assistant chief of police in Los Angeles. I’ve seen firsthand the danger assault magazines pose to police officers and the public. In 2005, José Raul Peña took his 19-month-old daughter hostage and engaged SWAT officers in an extended gun battle using a shotgun and 9-mm handgun with a large capacity clip. During the 2½-hour standoff, 140 shots were fired, Peña and his daughter were killed and a SWAT officer who attempted to save the little girl was shot through the shoulder. Here, in San Francisco, Gian Luigi Ferri used 40- and 50-shot magazines to kill nine and wound six others in the 1993 101 California Massacre…

Large magazines serve no useful purpose in civilian life except to extend shootouts, magnify carnage and suffering and put the lives of law enforcement officers and civilians at risk.