Filmmaker Peter Rodger was convinced his son was a victim in the horrific Santa Barbara, California shooting rampage last month (May14) after seeing his name mentioned in stories about the massacre. Elliot Rodger embarked on a vengeful killing spree on 23 May (14), shooting six people dead and injuring 13 others before turning the gun on himself as part of a protest against the University of the City of Santa Barbara girls who had rejected him. His father, who served as assistant director on 2012's The Hunger Games, has since revealed he found out his son was a killer via the Internet the morning after the tragedy - and the discovery left him speechless. In a candid new interview with U.S. broadcaster Barbara Walters, he says, "I thought he was a victim and it wasn't until 4.35am (the following morning) that I found out by going on the Internet that he was the main suspect and there was only one killer and when I saw that, it was like... it's one's worst nightmare; I can't describe the feelings." Elliot had left a journal detailing his murder "manifesto" and his dad admits he has struggled to mourn his death and find the will to forgive the 22 year old in the weeks since the massacre. He explains, "It's very hard... very, very hard (to mourn his death). After reading the journal, I had a lot of anger for him and I think my job now is to replace the anger with love and forgiveness, but at the same time I'm haunted by... this human being that changed and became something else." Walters went on to ask Rodger if he wished his son had never been born, to which he responded, "That's a really loaded question... Part of me says yes, and the reason is because he did an awful lot of harm to young men and women who didn't deserve to die, and my son did it." The full interview is due to air on America's 20/20 news show on Friday night (27Jun14).