Mohamed Noor shot Justine Ruszczyk Damond as she approached his patrol car to report a possible rape behind her Minneapolis home in July 2017.
He said the shooting was a mistake.
In court, Ms Damond's father, John Ruszczyk, called the killing "an obscene act by an agent of the state".
"Justine's death has left me incomplete - it is as if I have lost a limb or a leg," he said in an impact statement.
Ms Damond's fiancee, Don Damond, read an emotional statement addressed directly to her.