The British director whose son killed six people and injured 13 others near the University of California last month has pledged to help prevent future mass killings.
In a letter provided to ABC, Peter Rodger said he wanted to help people recognise warning signs of mental illness within families.
He says his son Elliot hid his sickness from his family, mental health professionals and law enforcement. Mr Rodger said in hindsight he is beginning to understand there are traits that family members can look out for in loved ones.
Mr Rodger also spoke to Barbara Walters in an interview for an ABC News prime-time special.
British-born Elliot Rodger died of an apparently self-inflicted gunshot wound after the May 23 rampage.
He had stabbed three people in his apartment in Santa Barbara, before heading outside to shoot dead three more victims.
Rodger, who had Asperger's syndrome, was found dead in his black BMW with a gunshot wound and three 9mm semi-automatic guns and more than 400 rounds of unused ammunition.