VERNAL — Vernal police say an 18-year-old man stabbed his father multiple times on Saturday.

Tristan Olsen was arrested for investigation of attempted murder. His father, Jeffrey Olsen, was stable at a Salt Lake City hospital, according to Vernal police.

On Saturday, Tristan Olsen got into an argument with his father while at a relative's residence, according to a statement from police. The argument escalated into a fight, during which Olsen stabbed his father six times in the arm and stomach, police stated. The father was initially taken to a Vernal hospital before being flown by medical helicopter to Salt Lake City.

Tristan Olsen claimed that as they were fighting, "his dad was trying to grab a knife. Tristan grabbed the knife instead and stabbed his dad," according to a Uintah County Jail booking report.

When police asked Olsen about a blood trail on the porch and driveway, "Tristan stated that after the stabbing they both went outside to the car to have a beer and a cigarette, though Tristan denied having any beer. At some point Tristan called his mother and told her about the fight and told her that he stabbed his dad. Tristan then handed the phone to his dad who talked to his wife and reported he was bleeding and to call 911," the report states.

Olsen's mother told police her son had been struggling with mental health issues recently "and has refused to go to the doctor to see what is wrong," the report states.