An 81-year-old Bucks County man was killed Sunday when he was trapped in an upstairs bedroom after his stepdaughter’s roommate lit a fire that cut off power to the chairlift he needed to escape the blaze, investigators said.

On Monday, prosecutors charged a Scranton man with homicide and attempted homicide, saying he stole his roommate’s car, drove to her parents’ house, and set a fire that destroyed the home and killed the stepfather.

Police in Dunmore, Lackawanna County, on Sunday arrested Christopher Gillie, 61, a few hours after he broke into Phyllis and Julius Drelick’s home in Buckingham Township and lit at least five small fires as the couple slept, according to the affidavit of probable cause for his arrest.

Julius Drelick was unable to escape and was later pronounced dead at the scene. An autopsy revealed he died from smoke inhalation and burns.

What compelled Gillie to drive two hours to set the blaze remained unclear. Bucks County District Attorney Matt Weintraub said Monday afternoon that detectives have “some idea of the motive,” but declined to elaborate.

“I can’t imagine the terror [the Drelicks] must’ve felt as they were separated by the fire, now forever,” Weintraub said.

Gillie had been living with Lisa King, Phyllis Drelick’s daughter, for some time, according to investigators. He also had been to the Drelicks’ home before, and was known to have had a somewhat contentious relationship with the couple, the district attorney said.

Gillie remained in custody Monday, denied bail. There was no indication he had hired an attorney. Court records show he was convicted in 2013 of setting fire to a vacant garage and home in Scranton. For that case, he served five years in state prison and was released in 2018, according to state prison records. He was on probation at the time of his arrest.

Phyllis Drelick, 85, told investigators that she heard a smoke detector go off just before 3 a.m. Sunday, as she and her husband were sleeping upstairs, according to the affidavit. She went to investigate, using the chair lift installed in her home to get to the first floor.

Halfway down the stairs, the lift stopped working when the fire caused a power outage at the home, the affidavit said. Drelick was able to climb down to the first floor, but unable to send the lift back up for her husband, who couldn’t descend the stairs without it, she told police. As the fire’s heat and smoke intensified, she fled to get help from her neighbor.

Drelick’s daughter called Dunmore police after hearing about the fire from her mother, the affidavit shows. King told investigators that her roommate, Gillie, was not home, and that her car and keys were missing.

A Dunmore officer later pulled Gillie over in King’s SUV, and smelled “a strong odor of gasoline” inside the vehicle, according to the affidavit. Gillie admitted to officers that he was drunk, and had the keys to the Drelicks’ house and a lighter in his pocket. An antique rifle that belong to the couple was next to him on the passenger seat.

Surveillance footage from a neighbor’s home recorded King’s SUV pulling into the Drelicks’ driveway and then away nearly an hour later, according to the affidavit.

For Weintraub, a disturbing mage was the broken lift. “I can’t stop thinking about that chair lift, frozen in place by this intentional fire,” he said.