Ladmarald Cates, who was fired following an internal investigation by the Milwaukee Police Department, was convicted Jan. 11 of violating the victim's civil rights.
Authorities said on July 16, 2010, Cates, 45, responded to the then-19-year-old woman's 911 call regarding someone throwing rocks and bricks through the windows of her home. He then coerced and intimidated the woman into committing sexual acts before raping her, authorities said.
"This officer committed a heinous act by raping a woman who called on the police because she needed help," Assistant Attorney General Thomas E. Perez said in a release. "His outrageous conduct requires the significant prison sentence delivered by the court today."
Cates said the two had met previously and maintained the sex was consensual.
The Milwaukee Journal Sentinel reported last year Cates previously had been accused of sexual misconduct with two female prisoners and a 16-year-old girl.
Assistant U.S. Attorney Mel Johnson said Cates' crime and those committed by other officers have led the community to lose trust in the Milwaukee police.
"The Milwaukee area is tired of it. It has to stop," Johnson said.