Steve Neavling

The FBI is investigating the death of a man who died while in police custody in Milwaukee after a newspaper report cast suspicions over the manner of death, the Associated Press reports.

A medical examiner changed the cause of Derek William’s July 6, 2011, death from natural to homicide after the Milwaukee Journal Sentinel detailed the last moments of his life.

Williams, 22, died in the back of a squad car after struggling to breathe, the AP reported.

A video shows Williams losing consciousness after he complained he couldn’t breathe.

He was pronounced dead 45 minutes later, following failed efforts to resuscitate him, according to the AP.