Dennis Rowley Gwyther, a 50-year-old flight attendant for SkyWest Airlines, was killed on May 22, 2019, while driving on Interstate 84 near Snowville in Box Elder County, Utah. He was commuting to Boise with a coworker when a Volkswagen Jetta pulled alongside their vehicle and the driver opened fire. Gwyther was fatally wounded and his passenger was injured but able to call 911.

The shooter fled and abandoned the Jetta in a creek in Idaho. Two days later a joint Utah–Idaho task force captured a suspect in southern Idaho after he allegedly had broken into a house and stolen an all-terrain vehicle. The suspect, identified as Jonathan Mendoza Llana, was charged with aggravated murder, attempted aggravated murder and multiple counts of felony discharge of a firearm. Investigators said they found no evidence of a hate crime or road rage and described the attack as random.

Prosecutors pursued questions about the defendant’s mental competency and he was sent for evaluation. No motive has been identified; anyone who knew Dennis, his route that day, or has information about the shooting is asked to come forward.