A former MetroAccess driver was found guilty today of sexual assaulting a passenger last year.

Ezra Porter of Upper Marlboro, Md. faces 20 years in prison and will be sentenced in September. From the Prince George’s County State’s Attorney:

On April 19, 2013, Porter was transporting a female passenger from her place of employment to her home in Bowie. The victim was the only passenger at the time. During the transport, Porter pulled the vehicle over and threatened to harm her if she did not remove her pants. Fearing for her safety, the victim removed her pants and Porter sexually assaulted her. After the alleged assault, Porter drove the woman home and she later reported the incident to police.

“Mr. Porter used his position to take advantage of a woman he thought could not stand up for herself and he attempted to threaten her enough to keep her from reporting him,” State’s Attorney Angela Alsobrooks said in a release. “Mr. Porter was wrong and I am proud of our victim for fighting back and helping us bring Mr. Porter to justice.”

The 51-year-old was hired and employed by MV Transportation, which screened his criminal background when he was hired in 2009. The oft–criticized company’s contract with WMATA ended last summer.

MV Transportation’s spokeswoman did not immediately respond to request for comment.