Former MBTA police officer faces federal charges for allegedly covering up assault at T station

Federal prosecutors have accused a former MBTA police sergeant of helping a fellow officer cover up a brutal assault on an unhoused man at the Ashmont MBTA station five years ago.

David Finnerty of Rutland, 47, was arrested Thursday after a federal grand jury indicted him on two counts of false reports, according to a statement from Acting United States Attorney Joshua S. Levy.

"For the good of the community and all the honorable officers and supervisors in the police ranks, misconduct of this nature cannot be tolerated," Levy said.

The charges stem from an assault by another MBTA officer on a man at the Ashmont Red Line station in the early hours of July 27, 2018. Authorities said Officer Dorston Bartlett used his baton to strike a 32-year-old homeless man multiple times.

Finnerty, who was Bartlett's supervisor, then allegedly helped Bartlett cover up the beating. Federal prosecutors say Finnerty falsified an arrest report and a briefing to his superiors about the incident.

Finnerty pleaded not guilty in federal court Thursday.

The assault and alleged cover-up were the focus of a public feud between MBTA Transit Police leadership and Suffolk County District Attorney Kevin Hayden.

The DA's office initially filed state charges against Finnerty — but Hayden dropped them last year, citing new evidence.

MBTA Transit Police Chief Kenneth Green then accused Hayden of letting the officer off the hook, even telling the Boston Globe that he would stop referring police corruption cases to Hayden's office.

Green applauded the new federal indictment Thursday.

"When the Suffolk County DA made the inconceivable decision to Nolle Prosequi this case we were astounded," he said in a statement to WBUR regarding Hayden's decision not to prosecute. "This indictment speaks for itself."

A spokesperson for Hayden declined to comment.

Finnerty's defense lawyer pushed back on the allegations in an interview.

Finnerty was, "in my opinion, cleared and exonerated by the Suffolk County District Attorney's office," his attorney, Brad Bailey, said. "I don't think that he should have been re-prosecuted."