"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' "Face the Nation" on Sunday.
"At the time deputies interacted with him, he was able to convince them that he was OK," he said.
It's not clear why the sheriffs did not become aware of the videos. Attorney Alan Shifman said the Rodger family had called police after being alarmed by YouTube videos "regarding suicide and the killing of people" that their son had been posting.
Doris A. Fuller, executive director of the Virginia-based Treatment Advocacy Center, said California law has provisions that permit emergency psychiatric evaluations of individuals who pose a serious threat, but that was never triggered.