A Chilmark police sergeant was commended last week for leading an investigation that led to the arrest of a Florida psychic who bilked a Chilmark woman out of nearly $3.6 million.

On Oct. 5, Sally Ann Johnson pleaded guilty to tax evasion in federal court in Boston. As part of the plea agreement, she will return the money to the elderly Chilmark woman. who has not been named. Sentencing is set for January 2018.

Sgt. Sean Slavin became aware of the scheme in November 2013, and began an investigation. When police learned that charges were not applicable in Edgartown district court, Sergeant Slavin turned over his evidence to the FBI.

At the selectmen’s meeting last week, police chief Jonathan Klaren said Sergeant Slavin was relentless and meticulous in the early part of the investigation, and his work was critical to the FBI case.

“I’m proud of the job Sergeant Slavin did on that case,” said Chief Klaren. “He set the foundation for a successful prosecution by the FBI.”

Bill Rossi, chairman of the Chilmark selectmen later offered high praise.

“It’s a nice thing to know that our police officers are looking out after our residents, for people being taken advantage of,” Mr. Rossi said. “I think we’ve got people on our police force that care about the community, and know about the community, and that’s a good thing.”