A Casper man is heading to prison on charges he assaulted his girlfriend.

Forty-six year old Roger Johnson was sentenced to 18-to-24 months at the Wyoming State Penitentiary, after pleading no contest to one charge of aggravated assault.

Prosecutors say in mid-June, Johnson became suspicious that his girlfriend was with another man and pushed her onto the floor and grabbed her neck.

The woman was able to get free, and investigators say Johnson pushed her into a mirror and told her to drive him to Cheyenne.

Court documents say the woman agreed to drive out of fear of being assaulted again, but was able to turn the vehicle around at Glenrock and return to Casper.

Officers later noticed bruises on the woman, and discovered that Johnson had a criminal history which included a number of false imprisonment convictions.