"The exchange of words got more heated until Rosales went into his apartment and retrieved a handgun and shot the maintenance worker several times," Oberg said.
"At that time, we had two other citizens on the apartment complex property who had firearms and drew their guns and shot at Mr. Rosales," he said.
One was a resident of the 120-unit complex while the other was a fellow maintenance worker. The wounded Rosales then went back inside his apartment, where officers subsequently found him dead of his bullet wounds after breaking down his door with a bomb squad robot about 5:30 p.m.
Oberg declined to name the two people who shot at Rosales.
Bailey, meanwhile, remains in critical condition at a local hospital. His family has asked that the name of the hospital not be released, Oberg said.
Oberg said the investigation is continuing to determine whether any charges should be filed. Ballistics information is being reviewed and witnesses are being re-interviewed.
"Everybody retells a story differently. Certainly, although we don't like people shooting at each other, particularly in a crowded apartment complex…they both indicated they feared for Mr. Bailey's life, their own lives and the lives of the other people in the complex," Oberg said of the men who shot at Rosales.
Oberg said Rosales does not have a criminal record in Utah but has been involved in "minor" incidents out of state. He declined to elaborate.