"It appears to be a murder-suicide," Harwood said in a release, adding that Bates' 13-year-old son who was in the house during the shooting was confronted by Hill but managed to escape to a neighbor's house, where police were called.
"He pushed the gun aside, confronted Tracy and punched him in the face several times," Harwood said.
The shotgun discharged again, but it is unclear if Hill was trying to shoot at the boy, Harwood said.
"Investigation indicates that Hill and Bates have dated for several years but recently broke up," Harwood said. They hadn't had any contact in the past two months, he said.
"We are unclear at this point as to what provoked [the shooting]" Harwood said.
Sevier County Sheriff Nathan Curtis said the shootings may have had to do with the recent change in their relationship.
Both bodies were taken to the Office of the Medical Examiner for an autopsy. Detectives continued to collect evidence at the scene well into the afternoon.
Sheree Harward, a neighbor who lives down the street, said she was surprised to learn who was involved.
"I like them both, and it is a shock to me that something like this could happen," Harward told The Tribune. "It doesn't follow what I know of them it just doesn't."
Officers from the Salina Police Department, Sevier County Sheriff's Office and the Utah Highway Patrol responded to the shooting.