A missing 13-year-old Pennsylvania girl has been found safe in the District, and authorities arrested the 20-year-old Virginia man she was with.

The girl, from Radnor Township, Pa., had been reported missing from the Philadelphia suburbs on Monday afternoon. Authorities located her and Ashley Ryan Hareford when they got off a Megabus at Union Station on Tuesday evening.

Police suspected the teen was with Hareford because he had been stopped near the girl's home the night before her disappearance. An officer had stopped Hareford -- who is from Grottoes, Va., about 40 miles northwest of Charlottesville -- because he had been seen in the area three nights in a row, said Cpl. Kevin Gallagher with Radnor Township police. Hareford told the officer that he was in the area looking for work, and the officer let him go because there was no reason to hold him.

At some point, police learned that the girl had been communicating with Hareford using social media, and they found recent Facebook photos of the two of them together. At least one of them was "inappropriate," Gallagher said.

After media outlets reported the girl's disappearance, Radnor police received an anonymous tip that the pair was near 30th Street Station in Philadelphia. U.S. marshals determined that Hareford and the girl took a Megabus to Washington, and authorities were waiting for them when they arrived.

"It was a peaceful resolution to this situation, which we're happy [about] 'cause obviously we have to remember she's 13 years old, we didn't want any extra trauma to be added into this," said Radnor police Lt. Christopher Flanagan.

The girl was evaluated to see whether she had any injures and was then taken to child services. She was later taken back to Pennsylvania and reunited with her family, Gallagher said.

Hareford was arrested in the District on a charge of being a fugitive from justice. He is wanted on a corruption of a minor charge in Radnor Township, and authorities in Pennsylvania intend to extradite him.

Gallagher said he expects that Hareford also will face additional charges, though police do not believe he abducted the girl.