CNN is reporting that the parents of Elliot Rodger were desperately trying to locate their son after viewing his last YouTube video and reading his manifesto on Friday evening.

Rodger sent the the 140-page document to two dozen people not long before he began shooting people on and around the University of California, Santa Barbara (UCSB) campus.

His mother, Li Chin, first viewed the document at 9:17 p.m. Pacific Standard Time, and then went to his YouTube channel, where she found his rant entitled “Retribution,” in which he outlined his plan to “slaughter” members of “the hottest sorority house” on the UCSB campus. She immediately called his father, Peter, as well as 911, and the parents set off for Santa Barbara from Los Angeles.

According to a family friend, they heard about a shooting on their way to the campus.

Elliot Rodger killed six and injured 13 in his rampage, which only ended after he slammed his car into a parked vehicle and shot himself in the head.