On May 23, 2014, in Isla Vista, California, a young man named Elliot Rodger took it upon himself to kill 6 people and injure 14 more near the campus of University of California, Santa Barbara, before turning a gun on himself and taking his own life.

In this “20/20” special we take a closer look at how Elliot came to commit such crimes and for the first time we hear his father speak out about the incident itself and describe what Elliot was like growing up. It is in fact the first time a parent of a mass murderer has ever spoken publicly on television about the crimes their child committed. In doing so Elliot’s father hopes to show other parents the warning signs which he missed in the hopes that something like this never happens again.