Patrick Hughes-Bygott, 22, who allegedly urged arriving police officers to "finish her off" entered a plea to general homicide in the Aug. 16 slaying of Ellen Hughes-Bygott, 56, in Bensalem.

It now falls to Judge John J. Rufe to hear evidence and to determine whether the killing was first degree murder, third degree murder or manslaughter.

The degree-of-guilt trial is expected to include testimony about Patrick Hughes-Bygott's mental state when he attacked his mother.

Ellen Hughes-Bygott had moved to Bensalem to help care for her elderly mother. She also was seeking a divorce from her husband, James Bygott of Montgomery County.

Patrick Hughes-Bygott, the couple's only child, had dropped out of the University of Vermont in February 2007, and had been acting erratically, according to court records. His father has told police that Ellen Hughes-Bygott, a nurse, also was suffering from mental problems, having been diagnosed with bipolar disorder.

Mother and son had tangled before. In January 2005, police in Abington charged him with assaulting her after she accidentally put his cell phone through the wash. But she refused to testify, calling it "God's will" if he attacked her again, police later said.

Patrick Hughes-Bygott has told police his mother frequently yelled at and taunted him.

"She called me a fat faggot. She hit me as a child," he told homicide investigators. "She was mean to me. She abused me."

Early on Aug. 16, Patrick Hughes-Bygott drove to his grandmother's house, quarreled there with his mother and stabbed her repeatedly - all while the grandmother, Margaret Hughes, pleaded for him to stop.

"He told me, 'She's too thin, she's sick, she has to die,'" Hughes, who was injured while trying to intervene, said afterward in a hospital emergency room, according to court documents. " 'He was like a mad man stabbing her. He wasn't my grandson. He knew enough to stop and tell me he wasn't going to kill me because he loved me.' "

Hughes called 911, but was unable to finish the call. With the receiver off the hook dispatchers "could hear yelling (and) screaming and it sounded like an individual on the other end of the phone was being attacked," a probable cause affidavit stated.

When police arrived, Patrick Hughes-Bygott told them that his mother was anorexic and that he had wanted to kill her to end her suffering.

"My mother was a stick figure and I had to kill her," Patrick Hughes-Bygott allegedly told police outside the house, according to court records.

One of the officers said he was going into the hosue to check on the woman.

"Finish her off," Hughes-Bygott allegedly replied. "Finish her off, please."