In the weeks and months leading to Friday's killing spree in Santa Barbara, local law enforcement confirmed they had interacted with the alleged killer multiple times.
The news that police had spoken with Elliot Rodger before his alleged killing spree, which injured 13 and killed seven including Rodger, has drawn attention to how police officers are being called to act in mental health matters.
Read: Santa Barbara Shooter Was Angry Girls Were 'Repulsed by Me'
In January Rodgers accused his roommate of stealing $22 worth of candles and held him on citizen's arrest. Police then booked his roommate on petty theft charges. Today they said that the roommate, Cheng Yuan Hong, 22, was one of three people in his apartment found stabbed to death by the suspect on Friday. The roommate had pled guilty to petty theft in the case, police said.
Last July police responded after Rodger claimed he had been assaulted, but police determined Rodger might have been the aggressor.
Rodgers was most recently visited and interviewed by the police in April after a family member became alarmed about YouTube posts by Rodger that mentioned violence and suicide. While Rodger's parents and social worker were concerned, police found the student to be polite during their interview.
Read: Elliot Rodger's Manifesto
In an interview on ABC News' "This Week," former FBI agent Brad Garett said it can be difficult for law enforcement to identify serious mental health disorders.
"At an alarming rate law enforcement are being asked to be law enforcers and psychiatric social workers," Garrett told ABC News. "When they are given a set of facts, they take them and they look at the individual...He was articulate, bright, lucid, not typically what they deal with day in and day out with people who have mental health issues."
According to his own manifesto, Rodgers was hoarding guns at the time of this interview. However, Garett said there was not much the police could do after interviewing him and not seeing additional warning signs or plans for eventual violence.
Additionally because to Rodgers was 22, there was little his parents could do without proof that he was breaking the law or about to break the law. Although his parents had provided him with access to multiple therapists and a social worker, they were no longer his legal guardians.
"Once he becomes an adult, he [has] the ability to acquire firearms, to have all of these very, very dark thoughts," said Garett. "Until he takes some action and law enforcement knows in advance that he's about to take this action, there's very little they can do. And the parents are unfortunately sort of stuck."
Read: Father of Santa Barbara Victim Sobs and Rails Against Son's Death
Read: Inside Elliot Rodger's "Twisted World"
After Santa Barbara Killings, Questions About Police Dealing With Mental Health Issues