EVERETT — A Machias man has admitted to killing his mother, stabbing his father and setting fire to their home two years ago.

Zachary Konicke, 32, pleaded guilty Thursday to second-degree murder, second-degree assault and first-degree arson. Domestic violence was considered a factor in all three convictions. He also admitted to using a knife as a deadly weapon.

“I was suffering a serious mental health crisis at the time I did these things,” Konicke said in a written statement to the court.

He faces up to 23 years in prison under state sentencing guidelines. That hearing is set for Sept. 27.

In the statement, Konicke said he cut his father with the knife before kicking him down a staircase. He was staying with his parents at the time.

Also, he said, “I stabbed my mother in the head and leg while she was face-down on the kitchen floor.”

His mother, Vicki Konicke, 58, hid in the bathroom to get away from him. She died in the burning house, in the fire her son started.

The father’s injuries required hospitalization and surgery.

Konicke said he decided not to pursue an insanity defense, which his attorneys previously told the court they were considering.

In recent months, medical professionals said they could not confirm or rule out whether Konicke had been living with mental illness, or whether he had a psychiatric break brought on by hallucinogenic drugs.

As part of the plea, the defense team and prosecutors agreed to recommend a prison sentence at the higher end of the standard range. Under their proposal, Konicke also wouldn’t be allowed to contact his father.

Rikki King: 425-339-3449; rking@heraldnet.com; Twitter: @rikkiking.