Chiefs Michael Kehoe and Kristen Ziman share an experience every law enforcement leader dreads—the peace of their communities was shattered by an incident of mass violence.

Chief (Ret.) Kehoe was the chief of the Newtown, Connecticut, Police Department on December 14, 2012, when a shooter opened fire in the Sandy Hook Elementary School, killing 26 people, 20 of whom were children. He was one of the first officers to enter the school after the shooting.

Chief (Ret.) Ziman led the Aurora, Illinois, Police Department following a horrific attack at the Henry Pratt Company on February 15, 2019, that left five people dead and five of her own officers and one civilian injured. Chiefs Kehoe and Ziman provide a firsthand look at the events of those fateful days, and they reflect on the experience, highlight lessons they learned, and provide valuable insight into how law enforcement leaders can be better prepared and better respond in the event that an incident of mass violence occurs under their watch.