A Whitefish man accused of killing his father during a dispute more than a year ago is scheduled to plead guilty to the offense next week in Flathead County District Court.

According to court documents, Tanner Lehnen Hosek, 27, will plead guilty by reason of mental disease or disorder to one count to an amended charge of mitigated deliberate homicide at 1:30 p.m. Thursday, Nov. 7. Hosek is currently housed at the Montana State Hospital in Warm Springs. He will remain there for the court hearing, appearing via Vision Net.

Hosek’s attorney, Will Managhan, wants Hosek to stay at the state hospital so he can continue to receive the appropriate medication. Flathead County Attorney Travis Ahner has indicated the state has no objection to the motion, according to court documents.

Hosek was facing one charge of deliberate homicide after law enforcement officials said he allegedly 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.

According to court records, Hosek’s initial assessment was performed Feb. 15, 2019. 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.

The report also detailed several criminal incidents that began in 2011. That year, he was charged with burglary in two separate incidents in Missoula; another incident in Missoula involved alleged drug possession. Also in 2011, Hosek was charged with burglary and assault and other offenses in a November incident in Douglas County, Washington. He received a two-year suspended sentence in that case.

In July 2012, Hosek was charged with selling dangerous drugs in Flathead County. In 2014, he was charged with burglary in Missoula and in 2017, he was charged with assaulting a public safety officer in Multnomah County.

In January 2018, Hosek was charged with two felonies involving the possession of a dangerous weapon, resisting an officer and battery of a peace officer in San Diego, California.

He spent several months in jail in San Diego before being released to the custody of his parents. He was examined at Warm Springs May 1, 2018.

During his most recent stay at Warm Springs earlier this year, a 26-page report was issued by Catherine Orrino, a social worker in the Forensic Mental Health facility at the State Hospital.

Part of her report indicated Hosek had been diagnosed as bipolar, schizophrenic and schizoaffective. He had used several medications in the past, including Haldol, Zyprexa, Doxepin, Lithium and Ativan.

In the assessment, Orrino said Hosek began using marijuana as a freshman in high school, then cocaine, mushrooms, heroin, LSD and methamphetamines. Hosek also said he had attended an outpatient chemical dependency program in Flathead County for seven to eight weeks in the past.

In the affidavit of probable cause filed by Ahner, when officers from the Flathead County Sheriff’s Office responded to a residence outside Whitefish on Wilderness Lane, they found Eric Hosek, 65, dead.

Tanner Hosek allegedly told officers he had used a knife to stab and kill his father.

Court documents in the assessment provided further details about the disturbing scene where the incident occurred on Wilderness Lane.

According to a man delivering a pizza to a neighbor, he saw Eric and Tanner Hosek physically fighting. The driver alleged Eric had Tanner bent over the fence and was choking him. The driver said he parked, got out of his car and told both men to “cool it.” At that point, he saw blood on both men.

The next day, July 9, 2018, Sheriff’s Detective Geno Cook spoke to Tanner Hosek at North Valley Hospital where Hosek was taken after the incident for treatment of a separated shoulder and a cut on his thumb.

After Cook read Hosek his rights, Hosek asked the detective why he had given him his rights. The detective replied that he didn’t know what happened and Tanner said “OK. It was pretty scary.”

According to the information in the report, Hosek said he was looking for a USB in his mom’s car when he saw his father approaching him “silently” with a knife. Tanner alleged he didn’t move until his father showed him he was actually going to do it (stab him). When Cook asked Tanner what his father was going to do, he stated “stab me.” Tanner said he was almost going to let him stab him because he was his father.

Tanner alleged when his father reached out to stab him, he blocked him. They both fell to the ground and the knife was dropped. Tanner ended up with the knife and said he had to “stab his father slowly to make sure he wouldn’t kill me.”

According to information from a coroner’s report, Eric Hosek was stabbed 10 times, including three that were at least 3 1/2 inches deep. The report said Eric Hosek had wounds to his face, head, chest, left wrist and back.

Also in the report, Tanner said he called police “on his father” July 8 because his father was driving drunk and for his general behavior. Tanner, who admitted to having mental-health disorders, said his father was telling him he was crazy and he was doing something wrong.

When the detective questioned Tanner once more about slowly stabbing his father, he replied “This guy is gonna (expletive) kill me if I don’t hit him first.”

Three days later, Cook interviewed Tanner’s mother, Linda (Dusty) Hosek about her son’s mental illness. She said Tanner had been in a psychotic state for the last two weeks, mostly going without any sleep. She said Tanner had isolated himself in his room and smoked marijuana.

She said Tanner had gone to Western State Hospital on July 5 and when he returned a couple of days later he told his mother that the mental-health people were going to help him get off his guardianship status.

Court documents indicate Tanner’s parents, Eric and Linda Hosek, were appointed his co-guardians in August 2015 to help care for him.

Tanner was a 2010 Whitefish High School graduate who played soccer at the varsity level. Another court document noted Tanner had attended the University of Montana in 2010, when he first reported his mental-health concerns. 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.”

Eric Hosek was a senior financial consultant with D.A. Davidson & Co., in Whitefish and had been with the company since 2001. 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.

Reporter Scott Shindledecker may be reached at 758-4441 or sshindledecker@dailyinterlake.com.