A trial of Casper man involved in a shooting last July is underway.

Twenty-year old Michael Cooper is facing one charge of aggravated assault after police say he opened fire on another person that was following him.

In their opening statements, the prosecution says Ronald Rodabaugh was trying to break-up an argument at the Loaf and Jug at Poplar and Collins Streets in Casper, when he noticed Cooper leaving the scene.

Rodabaugh told officers he followed Cooper in his car, with the intent to point him out to police, but a short time later, Rodabaugh says Cooper opened fire at him.

Rodabaugh then hit Cooper with his car out of self-defense, and then later pinned him between the car and a fence.

Afterwards, Rodabaugh ended up getting shot in the leg.

The defense says Cooper fired in self-defense because Rodabaugh was following with the intent of doing harm...and did not pull the trigger, until after he was hit by Rodabaugh's car.

The trial is expected to last until Wednesday, February 1st.