A homicide investigation spanning two states continues after a Utah man was killed and another injured in a shooting on Interstate 84 between Tremonton and Snowville late Wednesday night.

Utah Highway Patrol Lt. Lee Perry said 50-year-old Dennis Gwyther of Salt Lake City was killed in the shooting. The name of his passenger has not been released.

The shooting was reported by the passenger of a Range Rover, who called 911 just after 8 p.m. to report the shooting.

The details of the shooting remain under investigation, said Utah State Bureau of Investigation Lt. Ryan Van Fleet.

Early reports indicate there was an apparent slowdown on the Interstate at about 8 p.m. caused by two slow-moving semi trucks travelling side-by-side as one passed the other on Rattlesnake Pass, a steep incline on 1-84 westbound.

Van Fleet said the shooting occurred shortly after the truck in the fast lane moved back into the slow lane and traffic was able to accelerate, but it was not readily apparent if there had been some kind of interaction between the occupants of the Range Rover and the suspect.

“We have interviewed the passenger and there is nothing that he told us that that leads us to believe there was any interaction prior to the shooting,” said Van Fleet. “Nothing that we’ve been able to uncover so far indicates a road rage incident.”

The suspect vehicle is a silver Volkswagon Jetta registered to 45-year-old Jonathan Llana, who is considered a person of interest at this time. Van Fleet said investigators believe Llana is from the Las Vegas area.

Law enforcement agencies involved in the investigation have not confirmed he was behind the wheel at the time of the shooting, Van Fleet said.

The suspect allegedly fled the area and was later spotted in Idaho, where law enforcement officers from the Cassia County Sheriff’s Office and Idaho State Police attempted to stop him.

Llana reportedly fled from police in his vehicle until he eventually crashed in a rural area about 25 miles east of Burley and fled on foot, the Idaho State Police reported.

Llana is described as 5 foot 10, 150 pounds with black hair and brown eyes. The Idaho State Police said the man is considered armed and dangerous, and if he is seen, law enforcement should be contacted immediately at (208)846-7550.

State investigators in Utah have taken possession of both the Range Rover and the suspect’s Volkswagen Jetta, and they are being processed for evidence by the state crime lab.

Van Fleet said there was a firearm in the Jetta, but investigators had not yet determined that is was the same one used in the shooting.

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Amy Macavinta is the crime reporter for The Herald Journal. She can be reached at amacavinta@hjnews.com.