Barbara Walters interviews father of UCSB mass murderer

(WJLA) - "My son caused so much pain and suffering for so many families,” Peter Rodger tells ABC’s Barbara Walters as he struggles every day with the horror of it all.

“It's like a reverse nightmare situation. When you go to sleep normally, you have a nightmare and you wake up and, 'Oh, everything's OK.' Now I go to sleep, I might have a nice dream. And then I wake up and slowly, the truth of what happened dawns on me. And you know, that is that son was a mass murderer.”

Rodger’s 22-year-old son Elliot killed six people and injured 13 in a gruesome rampage last month near the campus of UC Santa Barbara. In a threatening video posted beforehand, the son vented about being long ridiculed and rejected by women. He had been undergoing counseling for years, but his father – a Hollywood film director who worked on “The Hunger Games” – told Waters he had no idea that his son was capable of such violence:

"There's no way I thought that this boy could ever hurt a flea. I mean, this is, this is the most unbelievable thing, Barbara. What I don't get is, we didn't see this coming at all."

Peter Rodger also lost his son that day as Elliot fatally shot himself after the rampage. You can watch Barbara Walters’ entire interview on ABC’s 20/20 Friday night at 10 p.m.