Updated

The relatives of two people killed in a 137-shot barrage of police gunfire in 2012 will split a $3 million settlement from the city of Cleveland, the attorney for one of the families said Tuesday.

Thirteen Cleveland police officers fired into the victims' car after a high-speed chase, killing 43-year-old driver Timothy Russell and 30-year-old passenger Malissa Williams in the parking lot of a suburban middle school. Both were unarmed.

Russell family attorney Terry Gilbert said the settlement of the federal lawsuit helps avoid long and expensive litigation. Williams' family attorney, David Malik, declined to comment Tuesday.

City spokesman Dan Williams would not comment on specifics of the agreement but said "the settlement speaks for itself."

Gilbert called the shooting "probably one of the worst cases of police misconduct" in U.S. history because of the number of police officers involved. More than 100 officers and 60 police cars, including some driven by supervisors, were involved in the chase. Gilbert said that by the time the chase ended in East Cleveland, officers had Russell's car blocked in and surrounded when they opened fire.

"We felt it important to address the conduct of all the shooters, not just officer Brelo," Gilbert said, referring to Michael Brelo, who faces two counts of voluntary manslaughter for having jumped on the hood of Russell's car and firing the last 15 rounds into the windshield. He fired a total of 49 rounds. Five supervisors face misdemeanor dereliction of duty charges.

Gilbert said the lack of supervision during the chase and shooting was evidence of a systemic problem within the police department that "led to the massive violations of the constitutional rights of Russell and Williams."

The chase began when officers patrolling near a homeless shelter on the edge of downtown Cleveland thought they heard a gunshot. Investigators later said it was likely that the officers heard Russell's car backfiring. That sparked a 20-mile chase that lasted 23 minutes and reached speeds of 110 mph.

The U.S. Justice Department is conducting an investigation of the Cleveland police department's pursuit and use of force practices.