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Grand jury indicts State Police trooper on assault charges for firing gun at ATV

Jessica Rinaldi/Globe Staff/File 2019/Globe Staff

A grand jury on Wednesday indicted a Massachusetts State Police trooper on assault charges for firing a rifle at an ATV in 2018, injuring the vehicle’s driver, according to the Suffolk district attorney’s office.

At the time of the shooting, Trooper Matthew Sheehan was “acting in his capacity as a law enforcement officer as State Police and other law enforcement agencies” tried to corral a group of more than two dozen people who were recklessly riding dirt bikes and ATVs in and out of traffic on Interstate 93 South on Feb. 24, 2018, according to authorities.

Police had activated their lights and positioned their vehicles in an attempt to contain the group, prosecutors said. According to authorities, Sheehan was the only law enforcement officer of the 13 who were present who fired his gun. The rider who was injured was Aderito Monteiro, a Randolph man who was 28 at the time.

On the day of the incident, Boston police received “numerous 911 calls during the day about a large group of people operating ATVs and off-road bikes erratically,” according to State Police. That agency reported seeing a group of between 25 and 35 people on dirt bikes and ATVs.


On Wednesday, a Suffolk County grand jury returned indictments, charging Sheehan with assault and battery with a dangerous weapon and assault with a dangerous weapon.

State Police spokesman Dave Procopio said in a statement that the department recognizes the “seriousness of the alleged offenses,” and will take “appropriate action” depending on the outcome of the judicial proceedings.

The shooting incident occurred shortly before Sheehan was suspended without pay, when the agency opened an internal affairs probe into inappropriate social media postings. He will remain suspended for the duration of the criminal proceedings and any subsequent internal investigation, according to Procopio.


Sheehan has a long history of posting racist and profane comments on a website called MassCops, including some in support of police officers who shoot suspects, the Globe reported last year.

Attempts to reach an attorney who has represented Sheehan in the past were not successful Wednesday evening.

In one 2012 posting, Sheehan said there was “no reason” why a police officer should ask a person to drop their weapon more than once before shooting. In others, he rants about criminals and often, people of color, using disparaging language, calling them “deadbeats,” “baby mommas’s,” “gang banging,” “EBT receiving,” “non GED getting,” and ”crack smoking.”

In another from 2012, in which he imagined a vigil after a police shooting, he referred to attendees as “None of Your Bidzness Rapper’s Delight Association.”

On Wednesday, prosecutors said Sheehan used his department-issued semiautomatic rifle that he retrieved from his cruiser as he responded to the Feb. 2018 encounter with the reckless ATV and dirt biker riders. He chose to use that weapon, and not the handgun that he and all officers carry on their hip, according to authorities.

Investigators determined Sheehan fired two rounds, one of which entered the side of the ATV’s tire, not the front.

“The angle at which the bullet struck the tire indicates the ATV was parallel to Trooper Sheehan, not heading towards him, thus not presenting the imminent danger that would permit the use [of] potentially deadly force in self-defense,” the district attorney’s office said in a release.


He is scheduled to be arraigned in Suffolk Superior Court on Oct. 10.

Suffolk District Attorney Rachael Rollins said in a Wednesday statement, “Members of law enforcement have a special role in society and overwhelmingly, these officers serve with distinction, courage, and compassion for the communities they protect.”

She continued, “Unfortunately, there are a small number whose actions are unacceptable, and, as we allege here, criminal.”

Eight people were arrested and charged with driving their vehicles recklessly in connection with the Feb. 2018 event, according to authorities. Seven of those cases have been resolved; one case remains pending, according to prosecutors. Rollins said those individuals are being held accountable, adding that their actions “should not have a prompted a trained law enforcement professional to respond with deadly force, as we allege.”

Andrea Estes and Evan Allen of the Globe Staff contributed to this report. Danny McDonald can be reached at daniel.mcdonald@globe.com. Follow him on Twitter @Danny__McDonald.