A Whitefish man who stabbed his father to death during a dispute more than a year ago was sentenced to 40 years, with 20 suspended, in the Montana State Hospital at Warm Springs.

Tanner Lehnen Hosek, 28, entered a plea of guilty by reason of mental disease or disorder to one count of mitigated deliberate homicide in November.

District Judge Robert Allison pronounced the verdict at the end of a lengthy hearing Thursday afternoon in Flathead District Court.

Hosek, who appeared via Vision Net, only said “I’m sorry this happened” when asked by Allison if he had anything to say.

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, at a residence just south of Whitefish.

He remains housed in Warm Springs. He will be under the supervision of the Montana Department of Public Health and Human Services. He received credit for the 563 days he has been incarcerated.

Hosek’s attorney, Will Managhan, asked for 30 years suspended.

“He’s clearly mentally disabled and I don’t think sending Mr. Hosek to 40 years is necessary,” Managhan said. “I don’t think 40 years will be necessary for Mr. Hosek to be fit for release. In homicide cases, I know they don’t automatically get paroled and I believe 10 years is appropriate.”

Managhan also referred to Hosek’s mother, Linda Hosek, saying she “has already lost her husband, she doesn’t want to lose her son.”

Linda Hosek didn’t speak at the hearing, but she did write a letter that was part of the pre-sentence investigation report.

Flathead County Attorney Travis Ahner acknowledged the difficulty of the case.

“This is a difficult case because of the circumstances,” Ahner said. “In my different discussions with Linda Hosek, she doesn’t agree with the state’s sentencing recommendations. She’s in favor of a 10-year commitment.”

When Judge Allison asked how the Montana Department of Public Health and Human Services handles parole, Ahner said the agency is obligated to do an annual review to determine where Hosek would be placed.

Managhan said if the department determines Hosek is no longer mentally ill, he can be released.

“But if he didn’t follow sentence recommendations, his probation could be revoked and he could be returned to custody,” Managhan said.

Judge Allison told Hosek “to keep up the good work” and that “I’m sure you don’t want another stain on your heart like this. You’re a young man and you have a lot of life ahead of you.”

Much of the hearing centered on how Hosek will be supervised and his terms of his release.

Judge Allison said he is concerned over Hosek being released, relapsing and ending up back in court because he didn’t like taking his medication or something similar.

But Managhan said Hosek had progressed since he was placed at the state hospital.

“My client has had a lot of difficulty in jail while not on medication, but the county jail is not equipped to deal with the mentally ill,” Managhan said. “He has a disability, but he’s not a bad person. I like him as a person.”

Hosek is a 2010 Whitefish High School graduate. Court document note that Tanner was a student at the University of Montana in 2010 when he first reported mental-health concerns.

Documents further indicate his parents were appointed his co-guardians in August 2015 to help care for him.

A July 2015 letter from a social worker who was a part of Tanner’s guardian hearing read, “Tanner remains stable at this time, but if he decides to go off his medications, per history, he is not capable of making rational decisions on his behalf. Eric and Linda Hosek are the most appropriate people to take on this guardianship and will do what it takes to keep Tanner safe.”

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

Eric Hosek was a senior financial consultant in Whitefish. He served on the Whitefish School Board and worked with the Whitefish Education Foundation. In addition, he served as a coach and was active in youth hockey.