New details have emerged that reveal more about the violent past of John Zawahri, the 23-year-old Santa Monica resident who shot and killed five people on Friday. In what seemed to be a planned attack, Zawahri killed his father and brother, then carjacked a vehicle and forced the driver to take him to the Santa Monica College campus where he shot and killed three others. Zawahri was then shot and killed by the police.

Early reports said that the Zawahri was angered about his parents divorce. Continued investigation shows that Zawahri grew up in an abusive domestic environment. His mother, Randa Abdou, had filed a restraining order on Zawahri's father with claims of verbal abuse and violence.

Though the anger against his father has been traced to his childhood, Zawahri's targeting of the school is a mystery. His father and brother were part-time students there, and Zawahri was briefly enrolled there.

Zawahri was previously hospitalized for making violent threats. In 2006, he was caught by an English Teacher at Olympic High, a school for troubled students, looking for assault weapons. He was hospitalized previously for violent thoughts.

Police are looking into the two weapons used by Zawahri and investigating whether they were permitted under California law. Authorities are trying to ascertain how someone with an array of documented mental problems and a history of violence was able to collect such large amount of ammunition.