WASHINGTON (AP) — Broadening its push to improve police relations with minorities, the Justice Department has enlisted a team of criminal justice researchers to study racial bias in law enforcement in five American cities and recommend strategies to address the problem nationally, Attorney General Eric Holder said Tuesday.

The police shooting last month of an unarmed black 18-year-old in Ferguson, Missouri underscored the need for the long-planned initiative, Holder said in an interview with The Associated Press.