CONCORD — A former leader at a New Hampshire youth detention center who was convicted of holding down a teen while he was raped in 1998 was sentenced Monday to 20 to 40 years in prison.

Bradley Asbury, now 70, was found guilty in November on two counts of being an accomplice to aggravated sexual assault.

Asbury had pleaded not guilty.

“With due respect to the court, I’m maintaining my innocence of these charges and do intend to appeal the convictions,” he said in the Manchester court before sentencing. “I would like to thank my family and friends for their support through this, through the process, for writing letters on my behalf and being here today. Thank you.”

Asbury’s wife, a stepson and a friend spoke on his behalf in court, saying he was a devoted family man and mentor.

Judge William Delker said he carefully read the letters, saying he believed Asbury is capable of showing the kindness that they described, but that that actually compounds the seriousness of what he did. Delker said Asbury took advantage of his authority and “crossed a line that cannot be crossed.”

Asbury served as a house leader at the Sununu Youth Services Center in Manchester. He was accused of restraining 14-year-old Michael Gilpatrick on a staircase with help from a colleague, while a third staffer raped the teen and a fourth forced him to perform a sex act.

Those four are among 11 men who worked at the detention center or an associated facility in Concord who have been charged since the state launched a broad criminal investigation in 2019. One defendant has since died, one was found incompetent to stand trial and charges against a third were dropped due to lack of evidence. Of those who have gone to trial, there have been two convictions and two mistrials.

Stanley Watson was convicted Jan. 13 of three counts of aggravated sexual assault against two boys. Jurors deadlocked last week in the case of Stephen Murphy, who was charged with raping Gilpatrick while Asbury held him down.

The Associated Press generally does not identify those who say they were victims of sexual assault unless they have come forward publicly as Gilpatrick has done.

At both trials, Gilpatrick, now 41, testified that he’d struggled to cope with the attack for many years and that talking about it at the trial was part of a healing process.

He said he wanted to hold the perpetrators accountable and recalled having an out-of-body experience during the attack. “I can see it happening, but I can’t do anything,” he testified during Asbury’s trial. “I was just not there. But there.”

Gilpatrick’s wife, Kelly Gilpatrick, addressed Asbury before sentencing Monday, saying, “the jury saw through you, and they saw you for who you truly are.”