A 16-year-old was shot and killed Saturday night and three others were wounded at a party in Oakley, where police responded to complaints 30 minutes before the shooting began.

According to a statement from Oakley Police Chief Paul Beard, officers responded to a report of a shooting around 11:12 p.m. on the 400 block of Shannon Way. Police found four people shot, including the 16-year-old, who died at the scene.

The three other victims were taken to John Muir Medical Center, where they were admitted with non-life-threatening injuries, police said. Beard said police are looking for a single shooter they haven't identified yet.

Police responded to noise complaints at the home about 30 minutes before the shooting. Beard said officers spoke with the resident, who said the party was being shut down and police assistance wasn't necessary.

Witnesses allegedly told police a group of 20-30 people tried to get into the party and, upon discovering the front door locked, went into the backyard through a side gate. Shortly afterward, they heard gunshots and saw people fleeing from the house.

Police found five 9mm shell casings during their investigation.