A Morrisville man who police say strangled his girlfriend at a Bucks County motel has been charged with murder, investigators said Tuesday.

Evan Smith, 37, was initially charged with aggravated assault, reckless endangerment of another person, strangulation and related offenses, after police were called to the room he had rented with his girlfriend of 18 years at the New Falls Motel in Falls Township, court records show. Prosecutors filed murder charges against Smith on Tuesday after the victim, Jamie Beighley, succumbed to her injuries on Sunday at Jefferson Bucks Hospital, according to the affidavit of probable cause for Smith’s arrest.

Smith remained in custody Tuesday, denied bail due to the nature of the charges. There was no indication he had hired an attorney.

Police were called to the New Falls Motel late Friday for reports of a woman in cardiac arrest, the affidavit said. When they arrived, they found Smith performing CPR on Beighley. Smith told the officers that “things got out of hand,” but became “uncooperative and combative” when the officers asked him questions, according to the affidavit. Smith then fled the motel in his car, nearly hitting an incoming ambulance on his way out.

Beighley, 36, had blood on her head, face and hands, and did not have a pulse. Medics were able to revive her, and transported her to Jefferson, where she remained on life support until her death Sunday, the affidavit said.

The wounds on her hands, including blood underneath her fingernails, seemed to have been inflicted during a struggle, police said.

Detectives later tracked Smith down as he sat in his car on Hunter Drive in Morrisville, and took him into custody. During an interview with officers, Smith told them that he and Beighley had gotten into an argument at the motel after smoking methamphetamine together earlier in the day.

Smith told the officers that during the argument, he choked Beighley until she lost consciousness, according to the affidavit.