Federal prosecutors have opened a civil rights probe of the Riverside Police Department, which is already under investigation in the shooting death of a black woman last December.

The Justice Department said today the probe will determine whether the department "has engaged in a pattern or practice of law enforcement misconduct, including using excessive force and discriminating in the way it provides police services."

Officials would not discuss the complaints that led to the probe but said they involved incidents in the city before and after the shooting of Tyisha Miller.

The Justice Department is investigating 10 police departments nationwide, including those in New York City and New Orleans.

The department can seek court orders requiring police departments to address any problems found.

The probe is in addition to a federal civil rights investigation into the Dec. 28 shooting of Miller, 19. Police found her apparently unconscious with a gun in her lap in a locked car parked at a gas station. When she suddenly reached for the gun after an officer broke into her car to remove the weapon, four white officers fired 23 bullets at her, hitting her 12 times, police said.

The Riverside County district attorney criticized the officers but decided there was no criminal intent. That decision has prompted demonstrations in Riverside.

The officers have been notified that the police chief intends to fire them. Their lawyer claims they are being made scapegoats.