Meagan Grunwald, 18, was convicted in May of aggravated murder and other charges from the January 2014 shooting, carjacking and chase.
The teenager was a willing accomplice of her older boyfriend who was killed in a shootout with officers, prosecutors said during her trial.
But Grunwald tearfully told jurors that 27-year-old Jose Angel Garcia-Jauregui forced her at gunpoint to drive through three snowy Utah counties and threatened her family.
While Garcia-Jauregui was the one who fatally shot Utah County Sheriff's Sgt. Cory Wride and injured another deputy, Grunwald was charged and convicted under Utah laws that allow an accomplice to be considered equally responsible for a crime.
In addition to aggravated murder, she was convicted of 10 other counts that included attempted murder, aggravated robbery and use of a controlled substance. She was found not guilty on one count of attempted aggravated murder.
She faces anywhere from 25 years to life in prison. Grunwald is ineligible for the death penalty because she was 17 when it happened.
The shootout and chase started when Wride happened upon the couple's pickup parked on the side of a highway.
Garcia-Jauregui had a warrant out for his arrest and gave the deputy a fake name. When Wride grew suspicious, Garcia-Jauregui stuck a gun out the truck's rear window and shot the deputy as he sat in his police cruiser.
Prosecutors said Grunwald then drove the couple as they fled, at one point hitting the brakes to give Garcia-Jauregui a better shot at another officer and helping to carjack a vehicle.
Grunwald's lawyer said his client was a terrified girl who had trusted an older, manipulative man.
Attorney Dean Zabriskie has said Grunwald plans to appeal her conviction.
SOURCES: FOX NEWS