Massachusetts cop who opened fire on black ATV driver caught making shocking racist comments online

A Massachusetts State Police trooper who fired his weapon at an off-road vehicle driver during a wild confrontation has a history of posting racist content on an online forum for law enforcement officers.

Trooper Matthew Sheehan fired his service rifle Saturday during an encounter on Interstate 93 between state police and up to three dozen motorcycle and ATV riders, reported the Boston Globe.

It's not clear whether 28-year-old Aderito Monteiro, who is black, was struck by the bullet, although he suffered a minor injury to his foot and claims he was shot.

Troopers arrested seven people, including Monteiro, after other drivers complained they had recklessly stormed the interstate.

The Globe reported that Sheehan posted messages of support and racist commentary under the name "Big Irish" on the website MassCops.

“Note to f*cking scumbags!” Sheehan posted in July 2012 after a state trooper shot and killed a man who allegedly drove toward him. “‘You try and run us over and you will die!!!! Good shoot ALL DAY LONG!!!!!!!”

A state police report claims Monteiro was doing "doughnuts" near an I-93 exit ramp and then drove toward a trooper and a Boston police K9 unit operator.

Monteiro complied when the trooper and officer ordered him to stop and lie down, and the police report -- which Sheehan did not write -- does not describe what led to the shooting.

The Globe reported that Big Irish shared biographical information on MassCops matching Sheehan's, and two sources also confirmed the trooper used that screen name.

Sheehan's computer has been seized by state police, along with his department-issued gun, cruiser and electronics.

“The tone and nature of these posts are repugnant and clearly do not reflect the values, ideals and opinions of the Massachusetts State Police,” said state police spokesman David Procopio. “If the author is confirmed to be a member of the Department, we will take appropriate action.”

The trooper was placed on paid leave after the shooting, which remains under investigation.

Sheehan posted in 2012 that police should have "no reason" to ask people to drop their weapon more than once before opening fire, and he ranted in others against criminals and people of color -- who he referred to as "deadbeats" and "baby's momma's."

He also complained that black people were likely to join gangs, drop out of high school and receive public assistance.

“I wonder when all of his Pastors/Reverends/Supporters from the 7th Church of the Tabernacle Coallation Crack Free Non Child Support Turn Your Life Around Free EBT Card Baby’s Momma’s None of Your Bidzness Rapper’s Delight Association will come out to the vigil???? Stay safe !!” Sheehan posted in 2012.

The newspaper reported that Sheehan posted on the site between 2012 and last year.

Monteiro was arraigned Monday on charges of failure to stop for police, disorderly conduct, negligent motor vehicle operation and having an uninsured ATV, cited for having an unregistered ATV and failing to stay in marked travel lanes.

He pleaded not guilty, and his attorney claims Monteiro was in "panic mode" and did not intend to drive toward officers -- and he points out the client immediately complied with police orders to stop.