Matthew Sheehan, a Massachusetts State Police trooper on indefinite suspension after making racist comments online, was arraigned Thursday on assault and weapons charges after he shot an ATV driver during a police confrontation in February.

Sheehan pleaded not guilty to assault and battery with a dangerous weapon, and assault with a dangerous weapon in Suffolk Superior Court. He was released on his own recognizance and was ordered to surrender any state-issued and personal weapons by Friday.

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 in a “reckless manner,” according to the Suffolk County District Attorney’s office.

Sheehan allegedly walked to his police cruiser and grabbed a service rifle despite having a handgun on his holster. He then shot Aderito Monteiro, a 28-year-old from Randolph, in the foot. Sheehan was the only officer to fire a weapon, the district attorney’s office said.

Initial reports indicated that Monteiro allegedly rode his ATV toward Sheehan, and presented “imminent danger” that justified the use of his weapon.

But the district attorney’s office said that investigators found one of the bullets struck the side of the ATV’s tire, not the front. Sheehan originally said he had aimed for the ATV’s engine block in order to stop the vehicle.

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 presenting as a threat, according to the DA’s office.

Sheehan was suspended without pay following the incident, and remains so during the course of the legal proceedings.

“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,” state police spokesman Dave 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.”

Sheehan is also one of dozens of state troopers 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.

In the aftermath of the investigation into the February incident, Sheehan also came under fire after t was reported 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.”

On a forum about an officer-involved shooting in Worcester in July 2012, “Big Irish” wrote, “Note to [expletive] scumbags!!!! 'You try and run us over and you will die!!!! Good shoot ALL DAY LONG!!!!!!!”

The user posted several messages of respect for fallen officers. He also shared identifying information, including his hometown, age and information on his 12 years in the department.