Prosecutors have dropped an assault charge against a man who castrated a transgender woman in Denver.

James Pennington, a 57-year-old Chicago-based airline pilot, pleaded guilty Monday to practicing medicine without a license, a misdemeanor, under a deal with prosecutors.

The unidentified transgender woman asked Pennington to perform the surgery and later suffered heavy bleeding. She objected to his prosecution.

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Pennington's lawyer says he offered to help someone who "is a victim of her own body" and is glad that his case brought attention to the struggles of the transgender community.

Chicago's WLS-TV, which first reported the deal , says Pennington was placed on leave by ExpressJet Airlines after his arrest.

Prosecutors will ask for Pennington to get two years of probation when he's sentenced Aug. 21.