Police immediately rendered first aid, but Evans was pronounced dead at the scene, according to a police news release.
Rudd, who was not hurt, was wearing a body camera, Johnson said; he did not yet know the contents of the footage.
Police later learned that Evans "had been consuming heroin and had made comments that he was going to be in a 'shootout with the police,' " according to the release. "[He] had also been involved in a physical altercation with his girlfriend. Due to the demeanor and actions of the individual she was fearful to report the incident to law enforcement."
Rudd has worked in law enforcement for 15 years, and has spent the last 13 of them with the Spanish Fork Police Department.
The shooting was the third by police in Utah since Wednesday, when a police officer in West Jordan shot a man who was reported to be suicidal and was barricaded inside his home with his wife and three young children. Sgt. Mitch Soper had climbed to a second-floor window to help the family out of the house, when the man, 27-year-old Kyle Lambrose, walked into the room, carrying a gun. Lambrose shot himself in the head; as he raised the gun, Soper also fired on Lambrose, striking him almost immediately after Lambrose pulled his own trigger, police said.
Early Friday, a man in Davis County died after a shootout with a Utah Highway Patrol officer. Sgt. Paul Kotter was securing a road work zone about 2 a.m. on Highway 193 near the intersection with Hill Field Road, roughly midway between Layton and Clearfield. Drew Moyer, 21, of Layton, drove his car into the closed area.
Kotter approached Moyer to tell him that the area was closed to traffic, when Moyer allegedly pulled out a gun and opened fire, striking Kotter three times. Kotter returned fire, and Moyer drove away. Moyer's car crashed into a water tanker truck at the construction site. He was found dead inside the car, apparently killed by a gunshot wound to the head. Investigators say the wound appears to have been self-inflicted, but they had not ruled out the possibility he was struck by shots fired by Kotter.
Reporter Michael McFall contributed to this story.