An autopsy determined that the gunman who killed 12 people at a southern California bar died from a self-inflicted gunshot, police said.
Ian David Long, a 28-year-old ex-Marine machine-gunner, fatally shot 11 people at the Borderline Bar and Grill in Thousand Oaks and a police officer who responded just before midnight Wednesday.
The officer exchanged gunfire with Long, who was found dead at the scene.
Ventura County Sheriff Bill Ayub said an autopsy determined Long fatally shot himself.
Authorities have yet to determine a motive and are exploring all possibilities.
Former Sheriff Geoff Dean, whose last day on the job was Friday, said investigators believe Long targeted the bar but do not know why.
Authorities described an attack of military efficiency.
When Long shot his .45-calibre pistol, he killed. All of the injured suffered cuts, bruises and other minor injuries in frantic attempts to escape the gunfire. Some smashed windows and jumped out.
His social media accounts have been taken down but a law enforcement official said Long posted about his mental state and whether people would believe he was sane.
Long grew up in Thousand Oaks and several people who knew him described him in disturbing terms.
Dominique Colell, who coached girls’ track and field at the high school where Long was a sprinter, remembers an angry young man who could be verbally and physically combative.
In one instance, Ms Colell said Long used his fingers to mimic shooting her in the back of the head as she talked to another athlete.
“I literally feared for myself around him,” Ms Colell said in an interview on Friday. “He was the only athlete that I was scared of.”
Police said Long had no criminal record. However, last April, yelling and loud banging noises coming from the home Long shared with his mother prompted a next-door neighbour to call authorities.
Deputies responded and a mental health specialist who assessed Long worried he might be suffering from post-traumatic stress disorder.
