The Suffolk County District Attorney’s office indicted Massachusetts State Police Trooper Matthew Sheehan on assault and weapons charges after he shot an ATV driver during a police confrontation in February.

Sheehan was one of 13 officers who confronted a group of 25 ATV and dirt bike riders who were riding down Interstate 93 South on Feb. 24, 2018. The Suffolk County District Attorney’s office said the drivers were behaving in a “reckless manner.”

Sheehan shot Aderito Monteiro, 28, of Randolph, in the foot. He walked to his police cruiser and grabbed a service rifle even though he had a handgun on his holster, according to the district attorney’s office.

Sheehan was the only officer who fired his weapon, the district attorney’s office states.

Sheehan was suspended in early 2018 after a Boston Globe article tied him to a series of racists posts online. He also is one of dozens of troopers who have been implicated in the overtime scandal.

In 2016, Sheehan made $233,351 with $100,401 coming from overtime. The following year, in 2017, Sheehan earned $237,467 with $87,804 in overtime pay.

He will remain suspended without pay throughout the criminal proceedings and any subsequent internal investigation, spokesman Dave Procopio said.

“The Department recognizes the seriousness of the alleged offenses contained in this indictment and will take appropriate action following, and based upon, the outcome of the upcoming judicial proceedings,” Procopio said in a statement. “Colonel Gilpin and her Command Staff expect and demand that all MSP members uphold the highest standards of integrity, on- and off-duty, an expectation that is shared and embraced by the vast majority of men and women who serve as state troopers.”

Procopio said the district attorney’s investigation was led by Massachusetts State Police detectives who were assigned to that office.

Initial reports stated that Monteiro allegedly rode his ATV toward Sheehan, but the district attorney’s office stated on Wednesday that investigators found one of the bullets struck the side of the ATV’s tire, not the front.

The angle at which the bullet struck the tire suggests that the ATV was parallel to Sheehan, negating the theory that the ATV was heading directly toward him and presented the level of “imminent danger” that warranted him firing his gun, the district attorney’s office said.

“Every day I have the honor of working with law enforcement officers who uphold the law and keep our communities safe,’’ said District Attorney Rachael Rollins. “Members of law enforcement have a special role in society and overwhelmingly, these officers serve with distinction, courage and compassion."

Eight people were arrested, the district attorney’s office said. Seven were prosecuted, though the office did not say how those cases were resolved. One case is pending in the Central Division of Boston Municipal Court, according to the district attorney’s office.

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“They are being held accountable,” Rollins said.

Sheehan came under fire after the Boston Globe reported that he had a history of making racists posts online under the username, “Big Irish.” The “MassCops” profile included posts calling people in particular neighborhoods, including Dorchester, “scumbags.”

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