Santa Barbara Shooter’s Father's Open Letter: 'We Have to Stop This'

— -- Peter Rodger, whose son Elliot shot and killed six people in Santa Barbara, Calif., last month, wrote the following open letter exclusively for ABC News. Rodger sat down with Barbara Walters for an interview that aired on "20/20".

It has been one month and three days since my son, Elliot, did the unthinkable. There has not been one conscious second that I haven't been thinking about the pain and suffering he caused for so many. The ripple affect of his actions has spread to countless thousands. I mourn for the loss of the young women and young men whose lives he ended. I feel for the victims and their families more than for the loss of my own son.

I do mourn for the lonely boy Elliot was, who disappeared because of a monster of an illness in him that none of us knew was so severe. I wish I could turn the clock back. There are so many "If only's."

I tried my best to do my duty as a father, but obviously my best was not enough. My duty now is to do as much as I can to try and stop this from happening again. Too many lives are being lost. Law enforcement professionals, teachers and health workers on the frontlines of the mental health crisis bear too much of a burden. And countless families struggle in silence with the consequences of mental illness each day.

We have to try and stop this. It will be a long journey involving the personal choices of individuals and families, public discussions, mental health reforms, a change in the culture – you name it. My sincere hope is that I can help by telling my story.

None of us understood what was in Elliot's head – he hid it from not only his family, but also from mental health professionals and law enforcement. Looking back now through a tragic hindsight, I have begun to understand that there are traits, markers if you will, that family members can look out for in loved ones.

It's important to note that the vast majority of mentally ill people are not violent. I am only speaking from my perspective and in the hope that families may be informed, vigilant and more able to take action. I am painfully and honestly trying to both reflect and learn more about what markers matter most. I am sharing my story and my initial reflections in an effort to save others from the kind of pain and suffering that Elliot caused.

To help families, I've created a small website with resources on mental illness and a place to share stories called AskForHelp.org. I hope you find the resources on that site useful. It is just a start and by no means comprehensive. I am just doing what I can under the circumstances with the help of family and friends. My simple message is, if in doubt about a family member, please ask for help.

Sincerely,

Peter Rodger