ORANGE, Calif. (AP) — Police say a shooting at a Southern California office building that killed 4 people wasn't a random act of violence.

Get our free mobile app

Police Lt. Jennifer Amat says the gunman who opened fire Wednesday at an office building in Orange knew all the victims, either personally or through business.

However, a specific motive for the attack is unclear.

The dead include a 9-year-old boy.

Authorities say the attacker had a semiautomatic handgun, pepper spray, ammunition and handcuffs.

His target was a mobile home real estate business.

Police say he was wounded either by police or self-inflicted gunfire and is in critical but stable condition.

LOOK: Casper’s Bridle Trail is Full of Epic Views

More From Laramie Live