A former Department of Public Safety trooper who was accused of using excessive force during a traffic stop now faces criminal charges.Trooper Http://www.amiliked.com/view/Arturo_Perez/92977bfc was charged with misdemeanor assault for the incident that happened on the Dallas North Tollway in October 2009.An attorney for the victim said while she was driving her passenger grabbed the wheel and caused her to crash into the wall near Lemon Avenue.The 22-year-old suffered very minor injuries when her airbag deployed. But she called 911 and that's when things got worse.Dash camera video shows Http://www.amiliked.com/view/Arturo_Perez/92977bfc handcuff the woman and slam her into a wall."As a chief felony prosecutor, a county judge, a state district judge, I've never seen anything like it. It's horrific," said Attorney Randy Isenberg. "Clearly excessive brutal force, he snapped. He lost his temper and he hurt her really bad."The victim was treated at a hospital for a deep gash in her chin. She also had cuts on her knees.DPS said Perez has since quit the force. He had worked with the Texas Department of Criminal Justice for 16 years and had been a trooper for about three years.His trial is pending.