An MBTA officer allegedly beat a homeless man. Then 2 sergeants tried to help ‘cover up that crime,’ authorities say.

An MBTA transit police officer allegedly beat a 32-year-old homeless man at Ashmont station last July, and two transit police sergeants allegedly tried to help him cover up what officials are calling “excessive and unlawful use of force.” Now all three are facing charges, according to a release from the Suffolk County District Attorney’s Office.Dorston Bartlett, 65, of Lynn, who has since retired from the force, is charged with assault and battery with a dangerous weapon and violating a person’s civil rights. He allegedly struck the victim “multiple times” with his baton during the early morning on July 27, 2018. He also faces charges of misleading a police officer — since he allegedly gave “false statements” to two responding Boston officers — and assault and battery “for allegedly grabbing and pushing the victim during the booking process that followed his arrest.”Sgts. David Finnerty, 43, of Rutland, and Kenny Orcel, 55, of Chelmsford, are charged with accessories after the fact “to assault and battery with a dangerous weapon,” the release said. All three men face a charge of “making a false report as a public officer or employee.”“These charges stem from the alleged collusion among all three to create a false incident report on Bartlett’s encounter with the victim in the hours following the assault,” the release says.The charges stem from indictments handed down by a Suffolk County Grand Jury following a “lengthy” investigation. Finnerty, a shift officer in charge, and Orcel, a shift patrol supervisor, were placed on administrative leave during the investigation, the release said. The three are planned to be arraigned on March 27.Through the evidence, officials believe Bartlett tried to arrest the victim on a charge of assault and battery on a police officer following the alleged assault. Finnerty allegedly “drafted a report” submitted by Bartlett and approved by Orcel, the release said. But another member of the force found out about Bartlett’s alleged “use of force” later that morning and watched the surveillance video from the train station. The victim was released and didn’t face charges, and the investigation began.“Words cannot express the extreme disappointment I have in the officers who violated the victim and the public’s trust in such an egregious manner,” Transit Police Chief Kenneth Green said in a statement. “However I refuse to allow the corrupt actions of these individuals to tarnish the vast majority of the men and women of the Transit Police who day in and day out wear their badges and perform their duties with honor and integrity.”District Attorney Rachael Rollins called the alleged matter “unacceptable at every level.”“The charges reflect an unprovoked armed assault by a uniformed officer on a vulnerable member of our community, followed by a joint venture with supervising officers to cover up that crime,” she said in a statement, noting that incidents like this “undermine” other members of law enforcement. “Crimes against public integrity are some of the most important that my office can bring on behalf of victims and our community, and I take them extremely seriously.”