A South Texas police officer who used a stun gun on a 76-year-old man during a traffic stop for an expired inspection sticker has been fired.

Victoria police said Monday that Nathanial Robinson was fired following an internal affairs investigation into the Dec. 11 incident. Police Chief Jeff Craig said Robinson violated policy areas including conduct and performance, use of force and arrest without warrant.

After Pete Vasquez was pulled over, he pointed out to Robinson the dealer tags on the back of the car, making it exempt from an inspection. As Robinson proceeded to arrest Vasquez, a scuffle ensued and Robinson used the stun gun.

Police say the criminal portion of the investigation, completed by the Texas Rangers, has been forwarded to the district attorney's office for review.