Santa Barbara County Sheriff Bill Brown on Sunday defended his agency's handling of a visit deputies made last month to the suspect in Friday's Isla Vista rampage that left seven dead.
In April, family members called the Sheriff's Department expressing concern about Elliot Rodger's health. The deputies said Rodger, 22, seemed to be fine and they did not take any action against him.
Brown told CBS News' "Face the Nation" that he wasn't sure whether the deputies checked to see if he had any weapons registered in his name. Had they done that, the check would have shown Rodger had legally purchased three guns. Because Rodger had never been institutionalized or held by authorities, Brown added, he was permitted to have the guns.
"Obviously, looking back on this, it's a very tragic situation, and we certainly wish that we could turn the clock back and maybe change some things," Brown told CBS.
The sheriff added that deputies who checked on Rodger followed procedure and that they were convinced he was not a harm to himself. Rodger, he added, had a "a very convincing story."
"During the course of his interaction with mental health professionals, he apparently had never been either institutionalized or committed for an involuntary hold of any kind," Brown added. "And those are the two triggers that actually would have made him a prohibited person in terms of a fire arms purchase. So he was able, sadly, to obtain those three firearms."
In a 137-page document Rodger wrote, he mentioned the sheriff's welfare check last month, saying his whole plan would have been foiled had the officer found his guns and writing, which were in his room.
"That would have ended everything," he wrote. "For a few horrible seconds, I thought it was all over."
The welfare check was one of three interactions Santa Barbara authorities had with Rodger.
In January, officials said, Rodger accused his roommate of stealing three candles worth $22 and performed a citizen's arrest. The Santa Barbara County Sheriff's Department eventually arrested the roommate and booked him on petty theft charges.
Last summer, he accused several people of assaulting him. But investigators concluded he was the aggressor in the incident and a detective suspended the case.
Rodger is suspected of killing six people before taking his own life Friday. Officials said he targeted his apartment complex, then a UC Santa Barbara sorority and then a deli.
The narrative of the violence described by authorities shares striking similarities to the statement Rodger wrote in which he described plans to kill people.
In that document, he outlines detailed plans for killing his roommates and then attacking a sorority in what he described as his "war on women."