COLUMBIA, S.C. - The South Carolina state trooper who arrested NFL defensive lineman Sam Montgomery at a traffic stop last June has been fired.

The state Department of Public Safety said Friday that Lance Cpl. R.S. Salter was terminated for violating agency policies including conduct unbecoming a state employee. Salter stopped Montgomery in June when the Cincinnati Bengals defensive lineman was returning to his Greenwood home.

Montgomery was arrested and spent a night in jail after Salter clocked him going 89 mph in a 55 mph zone. But the trooper's dashboard camera also captured the officer threatening to use a Taser because the 6-foot-3, 262-pound lineman was struggling to understand his commands.

The agency said Salter's interaction with Montgomery was inconsistent with how troopers are trained to conduct themselves during such traffic stops.