AUBURN – A Mechanic Falls man who served five years in prison for battering his baby son was convicted Wednesday on four counts of sex-related crimes involving an underage girl.

An Androscoggin County Superior Court jury found Rocky V. Crowley, 48, guilty of sexual abuse of a minor, unlawful sexual contact and two counts of unlawful sexual touching. Each is punishable by up to 364 days in jail. He was acquitted of two related felony charges.

Crowley also must register as a sex offender for at least 10 years, a prosecutor said. He is expected back in court in late December for sentencing. He remains free on a $5,000 unsecured bond.

The charges stemmed from Crowley’s contact with Amanda Vadeboncoeur of Mechanic Falls starting when she was 14 years old. Her best friend at the time was Crowley’s stepdaughter and Vadeboncoeur spent a lot of time at the Crowley home.

It took the jury of five women and seven men about 3½ hours to reach a verdict following the two-day trial.

Vadeboncoeur testified that she had come to regard Crowley as a surrogate father and felt loved by him and his family. He was lenient and let the girls smoke and drink, buying them cigarettes and alcohol, she said.

He started out hugging her. Over time, he often grabbed her buttocks, she said. Crowley then began calling her into his bedroom at his home where he molested her, she said. She tried to avoid him after that, but his stepdaughter would tell her Crowley wanted to see her in his room.

She didn’t report the abuse at first. It was unexpected and she was scared, she said. She didn’t know what to do.

“It was embarrassing,” she said. “I didn’t want people to think I was stupid to let this happen to me.”

He told her he couldn’t wait until she turned 18 to have sex, she said.

Eventually, she told her boyfriend, who told his mother. She urged Vadeboncoeur to tell her parents. They notified authorities.

Crowley testified during the trial, denying any improper contact with Vadeboncoeur. His stepdaughter also took the witness stand, her testimony agreeing with Crowley’s.

Vadeboncoeur stood with her family on the courthouse steps after the jury delivered its verdict. “I’m just so happy it’s over,” said a tearful Vadeboncoeur, now 17.

“They’ve been calling her a liar for two years, but they can’t call her a liar no more,” said her father, Jim, holding her tight to his side.

“It’s been tough, real tough, knowing you couldn’t protect your child from somebody like that,” he said. “The guy needs to be off the streets. He’s a menace to society.”

The prosecutor in the case was pleased, despite the split verdict.

“We’re very happy,” said Assistant District Attorney Deborah Cashman. “It shows that Amanda’s story was heard and believed.”

While coming forward with sex-related charges is difficult, Cashman said Vadeboncoeur “never wavered” in her willingness to go to trial. She encouraged others to follow Vadeboncoeur’s example.

Crowley’s attorney, Michael Dubois, couldn’t be reached for comment Wednesday.

In the 1990s, Crowley served five years of an eight-year sentence in prison for aggravated assault and endangering the welfare of a child in connection with the death of his 2½-month-old son, who apparently suffered 29 rib and leg fractures before he died. The boy was found dead at a motel where Crowley was staying.