MEDFIELD, Mass. (AP) — Federal authorities said Thursday they have someone in custody after a developmentally disabled 17-year-old from Massachusetts reported missing by her parents was found safe in Rhode Island.

Rhode Island U.S. Attorney Peter Neronha said in a statement the person will make an initial appearance Friday in federal court in Providence, when further details will be given.

Brittany Thompson was spotted walking down a street in Coventry, R.I., at about 7:30 a.m., Medfield, Mass., Police Chief Robert Meaney Jr. said. She had last been seen on surveillance video leaving the Medfield public library with a man her parents said she may have met online.

"I want to emphasize the fact that she is safe, she is unharmed, she is OK," Meaney said Thursday morning, adding that she was brought to Coventry police headquarters where she was reunited with her parents. It's about 50 miles from Medfield to Coventry.

Brittany was found with a man, but Meaney said it was not immediately clear if it was the man seen on the library surveillance video. Meaney said case was under investigation but there were no state criminal charges immediately pending.

Authorities had said that Brittany appeared to have left the library voluntarily and was not abducted, but at a news conference Wednesday, Meaney said she may be in danger.

Brittany is a high school senior, but the chief said she has "developmental issues" that affect her "ability to make safe decisions."

At a news conference Wednesday appealing for her return, Maureen Thompson described her daughter as a "sweet, sensitive, innocent, but very emotionally young girl."

Her father said Thursday that Brittany was in good spirits, and her mother thanked people who "watched out for her" and gave tips to police.