LOS ANGELES (AP) _ The death of a college student who died after he was arrested outside a Grateful Dead rock concert was homicide because he was choked while officers wrestled him down, coroner's officials said.

Patrick Shanahan, 19, of Fountain Valley was high on the hallucinogenic drug LSD but died outside the concert in suburban Inglewood earlier this month from ''compression of the neck during restraint,'' according to a Los Angeles County coroner's autopsy report released Thursday.

''It's not an accident, not a suicide, it's a homicide - meaning death at the hands of another,'' said coroner's investigator David Campbell.

The district attorney's office is investigating and there is a possibility of criminal charges, spokesman Mike Botula said Thursday.

''It might be that even though there was the death of a suspect involved, the police may have acted properly,'' Botula said.

Witnesses reported seeing Inglewood police officers beating Shanahan with night sticks during his arrest after a Dec. 10 concert. The officers said they approached Shanahan because he was crawling on his hands and knees and screaming.

Inglewood police refused to comment on the coroner's ruling Thursday. Previously, police denied that officers either struck Shanahan or used excessive force, saying he resisted arrest and probably died from a drug overdose.

Shanahan, a student at the University of California, Santa Barbara, stopped breathing after six officers placed him in a patrol car, Inglewood police said. He was pronounced dead at a hospital.