Updated

Elliot Rodger created an extensive record of writings and videos before he killed six people and left 13 others wounded in a rampage near the University of California, Santa Barbara. His motive was clear: He wanted to exact revenge on those he felt had contributed to his lonely existence. However, there still are many questions and missing details about events surrounding the May 23 attacks.

THE DEATH OF HIS ROOMMATES

In his writings, Rodger voiced contempt for his roommates. His killing spree began at his apartment in Isla Vista, where he stabbed to death Cheng Yuan Hong, 20, and George Chen, 19, along with Weihan Wang, 20, who either lived there or was visiting. It's not clear how the slightly built Rodger was able to kill three people without attracting attention in a crowded apartment complex. Rodger wrote in his manifesto that he would start his rampage at his apartment to establish "my personal torture and killing chamber." At another point he envisions stabbing his roommates to death while they slept. Police have released no information about how they believe the stabbings were carried out.

THE DEPUTIES AND THE VIDEOS

Family spokesman Simon Astaire said Rodger's mother became alarmed in late April after viewing bizarre YouTube videos posted by her son. She notified his therapist, who called health officials who in turn notified the Santa Barbara County Sheriff's Department. Family attorney Alan Shifman has described the videos as "regarding suicide and the killing of people." Deputies interviewed Rodger on April 30 outside his apartment and found him composed and courteous, with no signs of mental distress that could lead them to consider confining him for a psychiatric evaluation. But deputies had not seen the videos that prompted the initial call and would not be aware of them until after the shootings. It's not clear why that information never reached the sheriff's office, and it's not known what specific information they were given before making the visit.

THE THERAPISTS

Officials and his family have said Rodger was in mental health therapy for many years, though apparently no official diagnosis of a mental illness was ever made. Rodger referenced in his manifesto the "useless advice that every other psychiatrist, psychologist and counsellor had given me." The family spokesman told ABC's "Good Morning America" in an interview aired Thursday that he was told Rodger was taking the anti-anxiety drug Xanax in the past six months after previously refusing to take medication. Beyond that, little is known about the details of the therapy, and it's not clear if or when that information will be disclosed, given medical privacy laws.

THE INTERVIEW

Rodger wrote that when deputies visited him on April 30 they spoke for only a few minutes and they asked him if he had suicidal thoughts. "I tactfully told them that it was all a misunderstanding and they finally left," he wrote. California has a law that allows authorities to confine people for up to 72 hours to judge their mental stability, but authorities have said that during the interrogation he did not exhibit any signs of trouble. Santa Barbara County Sheriff Bill Brown said Rodger "was able to make a very convincing story that there was no problem." No record of that interview has been released so it's not known what information deputies had at the time, what they asked or how they described Rodger.

THE WEAPONS AND THE VIDEOS

Rodger used a Glock 34 and two Sig Sauer P226s during his rampage. The guns were purchased individually from licensed dealers in Goleta, Oxnard and Burbank, and Rodger registered them. He wrote that they were in his apartment when police visited on April 30. Had police taken him into protective custody for a psychiatric evaluation they could have seized the weapons. Rodger posted at least 22 YouTube videos. He uploaded most in the week leading up to April 26, when he initially planned to carry out his attacks. He postponed his plan after catching a cold. After he was interrogated by deputies, Rodger wrote that he removed the videos from YouTube. He re-posted at least some in the week leading up to the killings. It's unclear if other videos exist that were restored to YouTube.