The Justice Department is launching a broad civil rights investigation into the Ferguson Police Department after an unarmed black teen was shot, leading to protests, unrest and more abuse from local cops.

The Washington Post reports that the investigation is expected to be announced as early as today by Attorney General Eric H. Holder Jr.

The Justice Department civil rights division, which has investigated excessive force in other police departments, will lead the probe.

The investigation will also include police departments in St. Louis County.

Investigators will be determining whether the department adopted polices and practices that led to civil rights violations.