The shooting occurred in the area near 3200 West 3500 South.
Assistant Police Chief Mike Powell of the West Valley City Police Department said around 7:30 p.m. a West Valley City officer made contact with a suspicious man. That man allegedly produced a knife, and at least one shot was fired by the officer.
"What we have right now is a male individual who has been struck by gunfire," Powell said. "He is in critical condition. The officer was not injured in this particular instance. We have no outstanding suspects and there is no additional threat to the public."
The identity of the suspect has not been released, but police said he is a 24-year-old Salt Lake Valley resident.
The officer who was involved in the shooting is on paid leave pending an investigation into the incident, which is standard procedure. Powell said the officer in question is an experienced member of the force.
This was the first officer-involved shooting with a West Valley City police officer since WVCPD Chief Lee Russo was sworn in.
Russo said he believes the officer's decision to open fire was justified.
"I was impressed by the way that the officers were on scene, had organized [and] contained the scene, were isolating witnesses, making sure that evidence was preserved and getting the resources into place," Russo said. "I believe that our officers acted reasonably. I believe that our department responded to this promptly and is thoroughly investigating it."
Salt Lake County District Attorney will review the case to determine if the officer was justified.