In 2014, in the college town of Isla Vista, California, a 22-year-old man murdered six people and injured 14 others before killing himself. The killer didn’t suddenly “snap” one day out of the blue; he planned the attack and spiraled into crisis in the years leading up to it. 

The horrific incident left violence prevention experts wondering: What were the missed warning signs?

One person who held some of the answers was the killer’s mother, Chin Rodger. She has long avoided the media, fearing that speaking publicly would only hurt the victims’ families more. But 10 years later, she’s come to see a greater purpose – that  sharing what she knows about her son’s behavior before the attack could help others identify similar warning signs and prevent further violence.

By confronting and sharing the painful memories and evidence her son, Elliot, left behind, Rodger has contributed to the field of threat assessment – teams of people who specialize in collecting information on possible threats, connecting the dots and intervening before tragedy strikes. This week on Reveal, Rodger talks publicly for the first time with Mother Jones reporter Mark Follman.