Draper Police Sgt. Derek Johnson was mortally wounded about dawn when he pulled up to an accident scene, allegedly by the driver of a car that had gone off the road.
Johnson, 32, was able to drive about 3 blocks before crashing into a tree and was pronounced dead at a hospital.
Kris Szelag, a registered nurse who lived nearby, told The Salt Lake Tribune, she rushed to the shooting scene where fellow officers were performing CPR on Johnson. "I wanted to see if there was any way I could help," she said.
The investigation determined the driver of the crashed sedan had also shot a female passenger and then shot himself after firing at Johnson as he approached the vehicle. Both were hospitalized in critical condition at area hospitals.
"Johnson was never able to return fire," Draper Police Chief Bryan Roberts said.
The shooting was under investigation by the Unified Police Department.
A candlelight vigil for Johnson was held Sunday evening at the Draper City Hall.