Chris Rugg, a junior who is a film major at the University of California in Santa Barbara, regrets not helping mentally disturbed Elliot Rodger when he was his roommate.

Although Rugg observed signs of psychological disturbance in Rodger, he decided not to interfere in his personal matters at the time. Rugg vacated the room last June as he began feeling uncomfortable living with Rodger.

When the 22-year-old mentally disturbed man took his own life on May 23 after killing six people and injuring 13 others in Santa Barbara, California, Rugg was disappointed in himself for not helping his former roommate.

"I realized that if I am not surprised that this is something he would have done then why did I not say anything?" Rugg told ABC News.

Rugg believes that if he had continued staying with Rodger, he would have been probably dead by now. Among the six college students who lost their lives, two were his current roommates and one was a guest student.

Since the incident, Rugg has urged the community to spot troubled individuals before they set on a violent rampage.

Bianca de Kock, a 20-year-old student who survived after being struck with five bullets, said that she will be unable to forget Rodger's "smirky, grimacy smile" right before the gunfire started. "He wanted to do this. He looked happy about it."

Veronika Weiss, 19, and Katie Cooper, 22 - who were along with de Kock at the time of the shooting - did not survive the physical attack.

Sharrese de Kock, de Kock's mother, is surprised as to how the authorities misdiagnosed Rodger before the spree killing. "How did he slip through the cracks? It shouldn't happen," the mother said, ABC News reports.

Police officials apparently knew about the sexist psycho's scary YouTube videos when it was too late to interfere.

The killer posted his final video "Day of Retribution", featuring his murderous plans, at 9:17 p.m. the day of the assault. At 9:18 p.m., Rodger emailed a 137-page hate-filled manifesto to his parents and therapist. About nine minutes after the e-mail, first gunshots were fired and around eight minutes later, he ended his own life.

The sheriff's department said that deputies were unaware of his YouTube videos when they examined him on April 30, three weeks before the murder spree.