HARRISBURG - In a case the veteran prosecutor called "unique," a Dauphin County judge Thursday convicted a Harrisburg transsexual of sexually molesting a teenage boy she was supposed to be baby-sitting.

Judge Scott A. Evans issued the guilty verdicts on involuntary deviate sexual intercourse and other charges against Caprice Dennison, 59, at the end of a five-hour nonjury trial during which Dennison took the witness stand and insisted she is innocent.

Evans, however, said he believed the testimony of her accuser, who said he was 14 when Dennison showed him pornography and performed sex acts on him one night at her home in May 2011.

The boy reported the abuse to his mother immediately after it happened, Chief Deputy District Attorney Sean McCormack said

The verdict means Dennison, who was born male and is undergoing a transformation to a woman, will face at least 10 to 20 years in state prison when Evans sentences her in August, McCormack said.

McCormack, who has prosecuted many child-sex cases, said this is his first with a transsexual defendant. "It's certainly an unusual case," he said.

Defense Attorney Gary Kelley argued that Dennison's accuser made up the molestation account. In addition to Dennison, Kelley called several character witnesses, including a pastor, who said they have always known Dennison to be honest and God-fearing.

"You do not know what happened behind closed doors that night?" McCormack asked one of Kelley's witnesses.

"No," the woman replied.

Dennison, whom Kelley said has lived as a woman for 25 years, seemed stunned as she hugged supporters after the verdict. She handed them her jewelry while sheriff's deputies prepared to take her to the county prison.

Evans also ordered that Dennison be evaluated to determine whether she should be deemed a sexually violent predator under Megan's Law.

This story was updated to rewrite the headline.