Shot and killed by a Los Angeles sheriff deputies. On the evening of Thursday, June 24th, Zac was meeting a friend in a restaurant parking lot in Studio City to go see a movie. His friend was witnessed by police officers approaching an unoccupied vehicle, which he believed to be Zac's. When one of the agents confronted the man, he became combative and began struggling with the officer. A deputy went to the agent's aid, drawing his gun and ordering the suspect to the ground. A second man behind the wheel of a Toyota sedan, later identified by the coroner's office as Zachary Champommier, appeared suddenly, driving the vehicle toward the group witnesses said, striking a deputy, who was thrown up onto the car hood and windshield before falling to the ground. Deputies opened fire, striking the victim in the left arm, the bullet stopping in his chest. Zac was pronounced dead at the scene. It is believed that he merely panicked and hit the accelerator instead of the brake. The department has begun an investigation into the shooting.

Three weeks before that night, Zac had graduated with honors from Granada Hills Charter High School. In the fall, he would be heading for college. In high school Zac had been a band and orchestra member. He played the saxophone in Granada Hills' Highlander marching band. In the school orchestra, he played strings, usually the viola. Zach was the only child of a single mom, Carol. According to his friends, Zac was funny, talented, smart, handsome, lively, gentle, playful, idealistic. One of his friends noted that he always wore a chain with an angel wing charm, a symbol of his idealism.

In December of 2009, Zac wrote on his MySpace page that he wanted to get an education, see the world, meet new people, and then "I'll find that special someone, I'll learn everything I want to, I'll do what I want with my life and live in that house in the mountains and own a bookstore! Ya, that's actually what I want. No joke."