A 53-year-old TriMet bus driver was arrested Tuesday in connection with the sexual abuse of a 15-year-old girl.

Police took Christopher Alden Parker into custody at his Southeast Portland home. He was charged with third-degree sexual abuse, first-degree online sexual corruption of a child and violating a stalking order.

He was booked into the Multnomah County Jail and will be arraigned Wednesday.

Parker has been a TriMet bus operator since December 1981. He most recently drove TriMet's 32-Oatfield route, which travels from downtown Portland, through Milwaukie to Clackamas Community College in Oregon City.

Parker has been the focus of a sexual abuse investigation since March 28, when Portland detectives were alerted to an ongoing relationship between Parker and the girl, whom Parker met on a bus.

Investigators say the relationship began more than a year ago when the girl was 14.

TriMet placed Parker on administrative leave in mid-March pending an internal investigation stemming from concerns raised by a TriMet supervisor regarding violation of a policy related to friends and family riding without a destination and driving off route. During the investigation, TriMet contacted the police to determine if there was any possible criminal wrongdoing.