A Wyoming Highway Patrol trooper could face up to 20 years in prison for allegedly stalking his estranged wife and vandalizing her boyfriend's car.

Thirty-one-year-old Robert King made his initial appearance in Laramie County Circuit Court this (Wednesday) afternoon. He waived felony charges of stalking and property destruction and pleaded not guilty to a misdemeanor count of violating a protection order.

King, who's been a trooper in the Cheyenne area since December 2008, was placed on paid administrative leave on February 17, a day after Cheyenne police began investigating him for felony vandalism.

According to court documents, King's wife met with police on February 21 and told them she had reason to believe Robert had been stalking her for about two months.

She said she believed Robert was throwing rocks and snowballs at her house, scratching on her windows and constantly driving through her neighborhood. She also told police that, despite her repeatedly asking him to stop, Robert was calling her approximately 30 times a day.

On February 17, police interviewed King about vandalizing a car parked outside of his wife's house on February 12. King reportedly admitted to being in the area prior to the vandalism and admitted he had returned to key the car.

After the interview, police seized King's cell phone. Data from the phone showed King had called his wife 104 times between January 10 and February 16.

Police also used GPS data and mapping from King's patrol car and determined he had driven by his wife's house 46 times between January 11 and February 12, sometimes stopping in front of her house or down the street.

King was arrested on suspicion of violating a protection order late Monday night, after his wife heard rocks hitting the back of her house and called the cops. Police say King was dressed in black pants, a brown hoodie and a black beanie. He also smelled strongly of alcohol.

King is currently being held in the Laramie County Jail on $5,000 cash bond. His arraignment date has yet to be scheduled.