An accident occurred shortly before 1am in block 1500 on North Bristol Street.
While the agents were on their way, they received several reports of a shooting, said Anthony Bertagna, spokesman for the Santa Ana Police Department.
Upon arrival, the officers found a car perched on a retaining wall at Santa Ana College and a man with a bullet wound lying on the ground next to the vehicle. He was declared dead on the scene.
Bertagna said the detectives thought the man and his attacker were driving south before the accident, but the suspect fled in an unknown direction.
Inspectors will review videos from the college and a nearby McDonald's restaurant to see if the accident or shootout happened first, he said.