Transcript for Santa Barbara Rampage Victim's Father Looks to the Future
"20/20" continues. Once again, Barbara Walters. Reporter: Isla vista, a picturesque college community was shattered by grief. I just don't know why this happened to our son. It's crazy. This just doesn't make any sense. Reporter: Her son, George Chen, was only 19. We would die a hundred times, a thousand times. But we don't want our kids get hurt. Reporter: A junior at Uc Santa Barbara, George Chen was visiting his friends David Wang and James Hong, who were Elliot Rodger's roommates. The boys dreamed of one day starting a computer business together. And there are the two sorority sisters headed home that night from a day of senior week activities, excited about the summer ahead and looking forward to a future that will now never come. Katherine cooper dreamed of being a museum curator. She was very bubbly and she had that smile that she just made you smile. She was the brightest girl in the room. Reporter: Her math whiz sorority sister, Veronica Weiss, was described as wise beyond her 19 years. If it had been somebody else, she'd be the one here picking us up right now. Reporter: Have you reached out to the victims? To the families? I haven't reached out to them because I think that they needed to have space and time. And I think it would have been inappropriate. Reporter: Chin roger, Elliot's mother, has chosen to remain silent instead telling us in a statement, "I feel the world's attention should be focused on supporting the victims' loved ones and remembering the beautiful lives that were so tragically lost." We have heard from the families of some of the victims, and they resent my interviewing you because they hold you responsible in part for their children's death. What do you say to them? I wish I could turn back the clock. I wish that these families didn't have to go through this terrible ordeal. It's very hard for them to understand that I didn't know the monster that was in my son. Reporter: But one parent did reach out. Just weeks after that night, Rodger met with Richard Martinez two fathers embracing, searching for common ground. It was the most moving meeting I've ever had in my life. Reporter: Martinez's son Christopher was 20 years old when he became the last of Elliot Rodger's victims shot as he was entering that deli. He was an only child? He was our only child yes. He was quiet, kind, humble, graceful, funny. And at the same time, one of the most competitive people you would ever meet. Reporter: In the aftermath of his tragic loss, Martinez made an impassioned speech blaming the NRA for his son's death. They talk about gun rights what about Chris' right to live? When will this insanity stop? When will enough people say, we don't have to live like this? Too many have died! We should say to ourselves, not one more! Thank you. That's it. Reporter: Martinez is spending his time now focusing on a campaign to bring about what he calls common sense laws to reduce gun violence. No parent should have to go through this. The only thing I have left really is to try to find some meaning in my son's death. Reporter: Why did you decide that you would speak out? What do you hope that will accomplish? Well, there are holes in the mental health system. Reporter: In death as in life, his relationship with his son remains complicated. Do you feel like your son should have never been born? That's a loaded question. But part of me says yes. The reason is, he did bring a lot of harm to young men and women that didn't deserve to die. And my son did it. Reporter: How do you mourn a child whom others vilify? It's very hard, Barbara. After Reading the journal, I had a lot of anger for him. And I think my job now is to try and replace that anger with love and forgiveness. But at the same time I'm also haunted by the pain and the suffering and the terrorizing that this sick human being did to others. And I have to live that with that for the rest of my life. We thank peter for opening up his family's life to us. If you have a child who you think needs mental health advise, go to our websi
This transcript has been automatically generated and may not be 100% accurate.