On June 7, 2013, in Santa Monica, California, 55-year-old Samir Zawahri was shot multiple times and killed at the family home on Yorkshire Avenue by his younger son, 23-year-old John Zawahri. John also fatally shot his older brother, 24-year-old Christopher Zawahri, with a single gunshot to the chest, then set the family house on fire.

After the arson, John Zawahri carried out a shooting spree across Santa Monica. He carjacked a woman at gunpoint and forced her to drive to Santa Monica College, fired at a city bus—wounding three passengers—and shot at a police cruiser. He continued his attack on the college campus, killing and injuring others, and was fatally shot by police after an exchange of gunfire in the college library.

Authorities examined John’s background and mental health history while investigating motives. Reports noted a troubled past, including prior threats and a 2006 incident involving bomb-making materials that resulted in his admission to a psychiatric facility. Did anyone who knew the Zawahri family notice changes in John’s behavior before June 7, 2013?