ALFRED — A Old Orchard Beach man pleaded guilty to murder Tuesday for killing his roommate in their apartment last year.

William Popplewell Photo courtesy of the family

Dustan Bentley, 31, was arrested last March in connection with the death of 65-year-old William Popplewell. Bentley has been held without bail ever since and initially pleaded not guilty in June.

He changed his plea Tuesday during a hearing at the York County Superior Court. As part of the plea agreement, the Maine Attorney General’s Office agreed not to seek a sentence of more than 40 years in prison. The minimum penalty for murder is 25 years. His sentencing hearing is scheduled for May.

“Are you pleading guilty to this charge because you are in fact guilty of this charge?” Superior Court Justice Wayne Douglas asked.

“I am,” Bentley answered.

Investigators have shared little information about the incident, and a police affidavit was sealed early in the case. Tuesday’s plea hearing revealed previously unreleased details.

Assistant Attorney General Meg Elam outlined the case against Bentley in a short summary of evidence.  State police previously said Bentley and Popplewell met at a Portland homeless shelter two years before the older man’s death, and Elam said Tuesday that Bentley moved into Popplewell’s apartment at the Ocean Condos building in December 2018.

On March 18, a police officer from Old Orchard Beach went to the apartment at 7:30 p.m. to deliver copies of summonses to Bentley for unrelated traffic offenses. Elam said Bentley took a long time to come to the door, and the officer heard the sound of glass breaking while he waited. Bentley was dripping sweat when he opened the door and claimed he had been cleaning.

Less than three hours later, police officers returned to that apartment after a woman reported to dispatch that Bentley called her and told her he stabbed and killed his roommate. The officers found a car near the apartment door with the trunk open and lined with a shower curtain. They found Bentley inside the apartment hallway near Popplewell’s body, which was wrapped in plastic trash bags.

Bentley later gave conflicting statements to police about the fatal altercation, Elam said. He said Popplewell attacked him with a knife, but acknowledged that the other man was in poor health and used a walker. He also said his roommate must have fallen on the knife during their fight, and that he did not call 911 himself because there was no cellphone service in the apartment.

An autopsy determined Popplewell died from blunt force trauma, multiple sharp force injuries and ligature strangulation.

The defendant stood quietly with his lawyer as Elam recited the evidence that she would have presented if the case went to trial. He wore an orange jail uniform and glasses. He told the judge he was taking medications, including lithium, but those prescriptions did not impact his ability to think clearly about his plea agreement.

Afterward, defense attorney Joseph Mekonis said that Bentley changed his mind about a plea during a recent settlement conference in front of another judge.

“That was the day that he really came to terms with this being a murder,” Mekonis said. “He had wanted a trial up until 10 days ago and see what we could muster about his state of mind. But last week, he really understood that the state would prevail on the ‘knowingly’ aspect of this confrontation between a 30-year-old hefty guy and Mr. Popplewell, a frail 65-year-old man.”

The law defines murder as knowingly and intentionally causing the death of another person. Mekonis said he did explore a defense of abnormal state of mind, but no doctor would support it. Still, he said Bentley himself does not know why he killed Popplewell.

“Their friendship was a symbiotic one, but whatever happened this day, he lashed out,” Mekonis said. “It was certainly the worst day of his life, and he’s very sorry about that for Mr. Popplewell’s family. I don’t think he knows his own motive. I think it was more of a spur of the moment, psychological situation for Mr. Bentley.”

Elam said she did not have any doubts about Bentley’s state of mind at the time of the incident.

“We were convinced that the evidence was strong, and if this case had gone to a jury, he would have been convicted of murder,” Elam said. “And it appears that he was convinced of that, too, and decided to accept responsibility instead of having a trial.”

The courtroom was mostly empty during the brief hearing, and the few observers were police investigators. But the victim’s family will have the opportunity to address the court at sentencing.

An obituary described Popplewell as a man with a “huge heart.” He lived in Indiana and Maryland before moving to Maine, and his wife of 20 years died in 2009. His family wrote about his love of animals and nature, as well as fishing and canoeing in Maryland.

“Throughout his adult life he was known for helping others no matter what their need. He helped with repairs and errands or whatever was necessary,” his family wrote in his obituary. “He was there for friends in need, both young and old, with his sweet heart, encouraging words and sense of humor to help lighten things up during tough times.”