The man suspected of fatally shooting two men and injuring two others at a Halloween party near Covina had earlier fought with one of the victims, a detective said.
The shooting broke out at a home in the 17000 block of East Bellbrook Street, a neighborhood in the unincorporated county area.
The shooter had not been found.
Sheriff’s Lt. Patty Thomas said she didn’t know what started the fight. The shooter opened fire at partygoers and then left, according to a sheriff’s statement.
Ronnie Benitez, 20, of Covina died at the scene, according to the coroner’s office. A second man, who had not been publicly identified by the coroner’s office yet, later died at a hospital.
One wounded man was released from the hospital, Thomas said.
Detectives asked anyone with information about the shooting to call the Sheriff’s Homicide Bureau at 323-890-5500. Anonymous tipsters can contact Crime Stoppers at 800-222-8477 or at lacrimestoppers.org.