MILWAUKEE (AP) -

The Federal Bureau of Investigation has launched a federal civil rights investigation into the death of a man who died in Milwaukee police custody.

Derek Williams died in July 2011 after struggling to breath in the back of a squad. The Milwaukee County medical examiner changed the manner of Williams' death last month from natural to homicide following an investigation by the Milwaukee Journal Sentinel.

In a statement Wednesday, Milwaukee Police Chief Ed Flynn said he has told federal officials they are open to the investigation and will cooperate fully.
There's also a state criminal inquest into the death being overseen by a former Milwaukee County judge.

U.S. Attorney James Santelle said they are also considering a formal investigation into a possible pattern of civil rights abuses by the department.