A Whitefish man accused of killing his father during a dispute more than a year ago pleaded guilty to the offense Thursday afternoon in Flathead County District Court.

Tanner Lehnen Hosek, 28, entered his plea of guilty by reason of mental disease or disorder to one count of an amended charge of mitigated deliberate homicide.

He made his plea via Vision Net. Hosek is currently housed at the Montana State Hospital in Warm Springs. He will remain there until sentencing, which is scheduled for 1:30 p.m. Thursday, Jan. 23.

Hosek is facing a maximum term of 40 years under the supervision of the Montana Department of Public Health and Human Services, according to the agreement.

Hosek’s attorney, Will Managhan, wants Hosek to stay at the state hospital so he can continue to receive the appropriate medication.

“He is doing well there,” Managhan said.

Flathead County Attorney Travis Ahner said the state has no objection.

Thursday, Hosek appeared in a green sweatshirt and wore black-framed glasses.

District Court Judge Robert Allison asked Hosek if he understood the plea agreement, if he was clear-headed and if he was on medication.

Hosek affirmatively answered each question and said the medication “helps him think more clearly.”

Managhan questioned Hosek about his diagnosis of schizophrenia and bipolar disorders and he answered “yes.”

Hosek originally faced one charge of deliberate homicide after law enforcement officials said he admitted to stabbing his father, Eric Hosek, to death with a knife on July 8, 2018.

Hosek received a mental-health evaluation and was committed to the Montana State Hospital. He was first admitted to the state hospital in Warm Springs on Feb. 6 for an evaluation. His stay was extended for a 90-day period May 20 by court order and he remains there.

According to court records, Hosek’s initial assessment was performed Feb. 15, 2019. At the time, Hosek’s court-appointed attorney Ryan Peabody requested the exam to determine Hosek’s fitness to stand trial.

Court records indicate Hosek has had prior stays at Warm Springs and has been in mental hospitals in Washington and Oregon, as well as in the Netherlands.