A view of the Salmon River in the H.B. Van Duzer State Scenic Corridor along state Highway 18.

A 25-year-old man pleaded guilty except for insanity to second-degree murder on Thursday for killing a Tigard man he gunned down on the side of a highway in a road-rage encounter two years go.

Polk County Circuit Judge Rafael A. Caso sentenced Justin Nathaniel McAnulty to the Oregon State Hospital, committing him to lifetime supervision by the Psychiatric Security Review Board.

McAnulty fired nine shots at Dennis Anderson, 45, from the seat of his black BMW 550 on July 13, 2022, after trailing Anderson’s Subaru Forrester on state Highway 18. Anderson and his partner, Brandy Goldbury, had been headed home from Lincoln City.

Anderson had been trying to get away from McAnulty as both headed east on the highway. McAnulty had driven around Anderson’s Subaru and passed Anderson and then later waited on the side of the road before pulling out to again follow Anderson closely. Anderson then turned off the highway onto a gravel shoulder, near milepost 15 in Polk County, so Goldsbury could call 911.

McAnulty pulled up parallel to the Subaru and Anderson got out of the car, according to police. Anderson was standing on the shoulder when McAnulty immediately pointed a 9 mm handgun at him and fired, police said.

Goldsbury, in the front passenger seat of Anderson’s car, watched the shooting and narrowly escaped getting struck by bullets, according to police. She told police that the road rage behavior by the BMW driver appeared to occur after Anderson had sprayed his windshield wiper fluid, which may have blown back onto the black car behind them.

“I watched you holding the weapon with both hands and pulling the trigger over and over again. I will never unsee that,” she told McAnulty in court. “These actions are not of a man but a monster.”

State Police Detective Brian Eskridge led the investigation.Working with Grand Ronde tribal police, the Polk County Sheriff’s Office, Salem police and other local police agencies, Eskridge used a description of the gunman’s car to track the BMW’s driving path and identify the make, model and license plate number of the car and its driver.

McAnulty, of Beaverton, tried to conceal the crime by selling the BMW, crafting a bogus alibi, changing his appearance and hiding the gun used. The gun was later found in a community green space about a block from McAnulty’s parents’ house in a plastic sealable bag with a fully loaded magazine and a round in the chamber, according to court records. When he was arrested days later, McAnulty had a loaded rifle in his bed next to him, according to the prosecutor.

Senior Assistant Attorney General Tobias Tingleaf told the judge that police investigators are “somewhat frustrated” with the outcome of the case, but he said mental health evaluations by mental health experts from both the defense and the state showed McAnulty was suffering from a mental illness and in a psychotic episode at the time.

McAnulty was an Oregon State University engineering student whose life “went completely awry” in his early 20s with the onset of an unspecified schizophrenia spectrum diagnosis, according to his lawyer, Benjamin Kim.

“Words can’t describe how sorry I am. I didn’t know what was going on in my head,” McAnulty said in court. “I’m so sorry. I’m still trying to figure out why I did what I did.”