Prince William County Police released a composite sketch of a man accused of sexually assaulting a teenage girl outside a library.

A 14-year-old girl told police that a man approached her from behind outside the Potomac Library in Woodbridge at 5:30 p.m. Friday. The library was closed.

The man began talking to the girl, then sexually assaulted her. The man left when the victim received a phone call.

Police are looking for a white man, about 20 years old. He is about 6'3", with a thin build, a messy beard, and possibly a New Jersey accent. He was wearing a gray or white jacket with a turtleneck underneath, baggy jeans, white shoes, gray knit hat and small rectangle glass.

Anyone with information can call Crime Solvers at 703-670-3700 or 1-866-411-TIPS.