CHICAGO (AP) — Chicago police are investigating allegations that a now-retired sergeant forced a transgender woman to perform a sex act inside a marked police vehicle while he was on duty.

The Chicago Tribune is reporting that the details of the investigation are included in documents the paper obtained. Department spokesman Anthony Guglielmi says that after an internal investigation the sergeant was stripped of his police powers in early April and that he has since retired.

The paper says that police reports indicate that the woman reported to doctors at Rush University Medical Center that she’d been sexually assaulted after the alleged incident in March and handed over what she said was DNA evidence that implicated the sergeant.

Police have not identified the now-retired sergeant.

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