BUENA PARK, Calif. (AP) — Authorities served a search warrant at a Southern California storage unit as part of their investigation into a fugitive former Los Angeles police officer suspected of killing three people.

Irvine police Lt. Julia Engen said Saturday that evidence was collected late Friday night from the facility in Buena Park. She wouldn't elaborate on the nature of the evidence or say who had rented the storage unit.

On Friday, another warrant was served at a La Palma house belonging to Christopher Dorner's mother. Officers collected 10 bags of evidence including five electronic items.

Authorities suspect Dorner in a series of attacks that left three people dead, including a police officer. Authorities say he has vowed revenge against several former LAPD colleagues who he believed cost him his law enforcement career.