Fox Boston reported on Thursday night that Stephen Ardrey, 30, is expected to make an initial appearance in U.S. District Court in Providence Friday.
In a release earlier Thursday, the U.S. Attorney's Office in Rhode Island said they had taken a person into custody in the case, but did not offer an identity or explain the charge or charges.
Thompson, who has developmental issues that her family says can affect her decision-making, was seen on security video leaving the library with a man about 4:30 p.m. Monday. She was located about 7:30 a.m. Thursday.
Medfield Police had announced about 10:20 a.m. Thursday that Thompson had been located safe and unharmed in Coventry, RI, a suburb south of Providence, after a motorist spotted her walking on the side of a road with a man.
At that time, Police Chief Robert Meaney said that no charges were planned, but also indicated the matter remained under investigation by Rhode Island and Massachusetts officials.
According to a release Thursday afternoon from the U.S. Attorney's Office in Rhode Island, the U.S. Attorney's Office, detectives and officers from Coventry and West Greenwich and agents from Homeland Security Investigations were working together on the case.
"The first priority of all of law enforcement was to locate and reunite the young woman with her family. Now that the young woman has been reunited with her family, law enforcement is working diligently to gather and analyze the facts of the woman’s travel from Massachusetts to Rhode Island and any related activity up to the time that she was located today in Coventry," the release stated.
At that time, no person or persons had been criminally charged, the release indicated.
In Rhode Island Thursday, Brittany's parents told media they felt overwhelming relief when they were notified early that morning that she'd been found in Coventry, RI.
“I can't tell you how relieved I am," Maureen Thompson told reporters, according to a post on the WHDH-TV website. "It has to be because of you guys here and for everybody else that really watched out for her that she is with us today. It would not have happened without all of you, so thank you so much."