In a release from the sheriff's office, it is unclear what the woman told Childress about whether she retrieved the gun.
But the release said Childress, concerned Gover might return, asked Deputy Eric Werner to assist him, and told Werner he was concerned about the possibility that Gover had a knife and a handgun.
After a third deputy joined Childress and Werner, Gover returned in the car. The deputies saw an "intense, determined look" on his face and were concerned about his state of mind, according to the release.
Gover drove away and the deputies pursued him, finding the car abandoned a few streets away. Worried that Gover would return to the woman's home, the deputies went back, but they could not find Gover or the woman inside. The deputies were "extremely concerned they had a hostage situation," according to the release.
Childress went into the backyard and saw Gover pop his head up over a six-foot fence. Childress yelled at Gover that he was under arrest and told him to come over the fence.
Gover jumped into the yard, shoved his hand into his pants pocket, said he had a knife and then pulled his hand out and put it behind his back, according to the release. Werner joined Childress, and the deputies, seeing something black and shiny in Gover's hand, believed he was armed, according to the release.
Childress commanded Gover to show his hands and get on the ground. Gover yelled that the officers would have to kill him. He charged at Childress, who yelled at Gover to stop. Childress fired his handgun at Gover five times and Werner fired his shotgun once, the release said.
Deputies performed CPR until medics arrived, but Gover died.
Detectives found a set of black, shiny keys next to Gover after the shooting. Inside the home, detectives found the knife Gover allegedly used in the Tuesday assault and discovered the handgun in the safe, according to the release.
The Spokane Investigative Regional Response team is investigating the shooting. The case will then move to the prosecutor's office for review.
Gover had a long criminal history in Utah, according to a search of court documents. They range from a theft conviction in 1988 to a conviction for falsely obtaining a prescription in 2009. His only violent crime conviction was for an attempted assault while he was incarcerated in 1997.
As of the 2009 conviction, Gover was listed as living in Hyrum.
Gover and the woman had been dating for about a year, though Craig Chamberlin, spokesman for the sheriff's office, said he did not know whether Gover had moved to Washington.