PORTLAND —A former resident of the YMCA’s men’s dormitory program on Forest Avenue has pleaded guilty to murder for killing another man living there last year.

Robert Lancaster, 51, was sentenced to 35 years in prison Wednesday at Cumberland County Superior Court.

Police say Lancaster assaulted 60-year-old David Hannauer just after midnight on Jan. 12, 2024, in the fourth-floor restroom. Officers found Hannauer unconscious and severely injured. He died from his injuries the following day.

“I find this was a savage attack on a vulnerable victim,” said Superior Court Justice Deborah Cashman.

A prosecutor argued Hannauer was frail; he needed help walking and weighed less than 120 pounds. Hannauer had a “limited ability to defend himself” from Lancaster, Cashman agreed.

It’s unclear what prompted the attack. Lancaster’s attorney said his client said that Hannauer had pinched him first, but a prosecutor said there was no evidence that occurred.

Police said they later found the victim’s iPad in Lancaster’s room, but he has not been charged with robbery.

Hannauer’s family described him last year as a “free soul” who grew up in a musically inclined household in New Jersey. He traveled extensively, they said, living in New Mexico, Hawaii and Central America, before moving to Portland about a decade before his death.

Hannauer was particularly fond of the ocarina, a small, round wind instrument. He played regularly, including once for a renowned composer, and also loved crafting ocarinas from clay, his sister told the court.

“I will miss him as long as I live,” Katherine Hannauer stated in a letter that Assistant Attorney General Jennifer Ackerman read in court on Wednesday.

Hannauer also described the ways her brother protected their younger adopted sister from neighborhood bullies when they were growing up, and their closeness as adults.

“Knowing he met such a violent end haunts me,” she wrote.

Both men were residents of the YMCA’s men’s dormitory program, Ackerman said, which the organization says it offers through a partnership with the city and social services organizations. The YMCA states on its website that it conducts background checks “on each individual deciding to make the YMCA their home.”

Ackerman noted Lancaster’s criminal history included some low-level assault convictions, the latest of which was in 2012. Cashman agreed this was notable, but also said she found Lancaster’s history “modest,” consisting mostly of older charges.

The YMCA did not respond to a request for comment Wednesday.

Lancaster pleaded guilty under an agreement with prosecutors to avoid a stricter sentence. Murder convictions can carry up to life in prison.

Ackerman described in court the state’s DNA evidence and video footage, tying Lancaster to the assault. She said police spoke with another resident who witnessed and overheard some of the attack.

Video from the dormitory’s hallway cameras showed Lancaster going into the restroom after Hannauer, Ackerman said. Lancaster could be seen leaving more than once, she added, returning at one point with a belt.

Lancaster said in court that he didn’t dispute any of Ackerman’s account.

“Are you pleading guilty because you are in fact guilty of this charge?” Cashman asked.

“Yes,” Lancaster said.

Lancaster’s attorney Randall Bates said his client has suffered mental health issues “his entire life” and endured a difficult childhood. Bates said Lancaster was accepting responsibility by pleading guilty, sparing Hannauer’s family from a lengthy criminal trial.

Ackerman said she believes Lancaster is sorry, after observing him during one meeting they had to discuss a plea deal.

“He did appear to have genuine remorse for what happened, and what he did to Mr. Hannauer,” Ackerman said in court.