CANONSBURG, Pa. -- A fired southwestern Pennsylvania police officer has been charged with child endangerment for allegedly having sex with a 17-year-old boy even after learning the boy was a runaway from Virginia.

Robert Helphenstine, 39, was officer in charge of the Fallowfield Township police department in Washington County when the alleged crimes occurred in March. He was fired in August.

Police said Helphenstine met the boy from Chesapeake, Va. outside the Greyhound bus station in Pittsburgh. According to police, Helphenstine told the boy he was a police officer and took him home, where they twice had sex.

North Strabane police Detective John Wybranowski said Helphenstine sheltered the runaway for four days, gave him money, a cell phone and computer equipment.

When the boy’s family called Helphenstine to tell him he was harboring a runaway, police said Helphenstine did not take any official police action.

Helphenstine's attorney denies charges that Helphenstine didn't immediately contact authorities after learning from a national database that the boy was a runaway. Helphenstine helped the boy board a flight home three days after meeting him.

Helphenstine is charged with endangering the welfare of a child and official oppression, among other charges. He has a preliminary hearing scheduled for Nov. 20.