May 19, 2001 -- Early Friday morning, a woman walked into Chicago's police headquarters with a clue that helped lead them to a man she said sexually assaulted her.

She handed police the man's testicles.

The 42-year-old victim was distraught and brought the testicles to the front desk of the police station at about 3 a.m. Friday, according to police spokesman Thomas Donegan. She told police that she had bitten off the testicles of a man who assaulted her on a street on the city's South Side, near police headquarters.

"She brought the testicles to the front desk and police then took her to Mercy Hospital where she was treated and released," said police spokesman Thomas Donegan.

Erik Williams, 21, was charged with aggravated criminal sexual assault, according to Donegan. Williams made his way to Michael Reese Hospital for treatment and was charged with the crime and placed into custody.

Physicians attempted to reattach Williams' testicles and the attempt was unsuccessful, according to a hospital spokesman.

Williams was scheduled to appear in bond court today.

ABCNEWS.com's Rose Palazzolo contributed to this report.