The officers were identified as Sergeant Lee Sorensen, 56, and Officer Eric Estrada, 31, of the Tremonton-Garland Police Department.
A sheriff's deputy and a police dog also were shot and wounded in their car as they arrived to help at a neighbourhood in Tremonton on Sunday night. The deputy from Box Elder County was released from the hospital Monday and the dog was hospitalised in fair condition, police said.
"These officers are definitely heroes," Police Chief Chad Reyes in neighbouring Brigham City said at a news conference on Monday.
When police respond to domestic disturbance calls, "we really don't know what we're walking into", he said. "And they are one of the most dangerous events that we can be dispatched on."
Police received multiple 911 hang-up calls from a home in the city. A single officer from the Tremonton-Garland Police Department arrived first and was speaking to someone at the home when the man came out with a gun, police said in a news release.
"The male opened fire on the officer, striking and killing the officer," the news release said.
A second officer from the department who responded "was immediately fired upon by the same male suspect" and was killed.
After the officers were shot, bystanders persuaded the man to put down his weapon, police said.
Utah Governor Spencer Cox called what happened "a terrible and tragic night." He posted online that he joined the state in mourning the loss "of these courageous law enforcement officers" and ordered flags to be flown at half-mast.
The suspect was arrested on charges of aggravated murder.
Sorensen had served 17 years as a law enforcement officer and received multiple honours for his service to the community. He had recently been promoted to sergeant and was to be sworn into his new role on Friday.
Estrada had worked in the jail in Box Elder County and as a patrol officer before joining the Tremonton-Garland Police Department. His colleagues described him as a dedicated father and husband who loved being on patrol so he could interact with people in the community.
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