The former Marine accused of gunning down a dozen people in Wednesday's Thousand Oaks rampage may have been suffering from PTSD, officials say.Ian David Long, 28, is accused of opening fire inside the Borderline Bar and Grill, a popular college hangout in Thousand Oaks, California.
Authorities later found him dead near the establishment's front entrance.
Ventura County Sheriff Geoff Dean says prior to the shooting, Long had displayed erratic behavior commonly associated with post-traumatic stress disorder, a mental disorder triggered by trauma.
However, some mental health experts have disagreed with Dean's prognosis, saying it's unlikely PTSD would cause someone to react in such a violent manner.
Barbara Olasov Rothbaum, a professor in the Department of Psychiatry and Behavioral Sciences, says, "It's not PTSD. This is whatever else, what other pathology would cause someone to do this."