LEWISTON (AP) -- A Lewiston woman who was allegedly strangled by her son may have been carrying on a sexual relationship with both him and his wife, according to court documents.

Matthew Audet, 22, was being held in the Androscoggin County Jail following his initial appearance Tuesday in Superior Court on a charge of murdering his 47-year-old mother, Debra Audet.

A police affidavit quoted a family friend as saying the victim had a sexual relationship with her son that started when he was 8 or 9 years old. The affidavit also said Matthew Audet's wife Kayla, 19, told police that she, too, had a sexual relationship with Debra Audet.

According to the affidavit, Kayla Audet was preparing to leave her husband, and the pair had argued to the point of throwing their wedding bands against the apartment wall. She told police she later saw Matthew Audet choking his mother late Sunday on a mattress on the floor after the two had been drinking.

"Kayla described Debra as lying on her back ... and her skin looking pale," Detective Jennifer King of the Maine State Police wrote. "Kayla said Matthew was above Debra with either one or both hands on Debra's throat."

Police arrived at the Birch Street apartment around midnight after Matthew Audet dialed 911 to report that his mother had stopped breathing.

An autopsy Monday revealed that Debra Audet, who was suffering from cancer, had died of strangulation and her death was a homicide.

Kayla Audet told police that as she was gathering her belongings to move out, her husband came up to her and said, "I killed my mom, I killed my mom," the affidavit said.