ORINDA, Calif. — Five people were killed and several injured in a shooting at a crowded Halloween party here on Thursday night, the police said.

An officer was headed to the site of the party, at a short-term rental home, at 10:48 p.m. to investigate noise complaints. Two minutes later, the police received the first reports of gunfire, the Contra Costa County Sheriff’s Office said in a statement on Friday night.

Officers found “a highly chaotic scene that included gunshot victims, injured partygoers and numerous people fleeing the scene,” the statement said.

Three gunshot victims were pronounced dead at the scene and two others died at a hospital.

The authorities identified the victims, all of California, as: Oshiana Tompkins, 19, of Vallejo/Hercules; Tiyon Farley, 22, of Antioch; Omar Taylor, 24, of Pittsburg; Ramon Hill Jr., 23, of San Francisco/Oakland; and Javin County, 29, of Sausalito/Richmond .