Massachusetts State Police fired a trooper Tuesday for what the agency described as unacceptable conduct that included the use of racial slurs.
The incident occurred during a weekend confrontation with a motorist while the trooper was off-duty, the agency said in a statement.
The trooper, whose name was not released, was a member of the recruit training group that graduated in May and was under a one-year probationary period, the agency said.
"I am disgusted and disappointed by the conduct that occurred, which is the antithesis of the standards of conduct and personal behavior we expect and demand of our members," the state police superintendent, Col. Christopher Mason, said in a statement.
The races of the trooper and the motorist were not disclosed, and state police said no additional information would be released.
Officials did not provide details about the incident except to say the trooper "approached a male in a stationary vehicle" in Revere, a city of around 54,000 northeast of Boston.
"This subject is not fit to wear the badge or call themselves a member of the Department," Mason said. He said the decision to fire the trooper was made shortly after he and other officials learned of the alleged conduct Tuesday.
"We will have no tolerance for such conduct," said Mason, who ordered an investigation. He has also asked the state attorney general's office to review the incident for any potential criminal or civil rights violations.
Gov. Charlie Baker appointed Mason as superintendent of the state police a year ago with an aim to implement reforms to improve accountability, among other measures.
Among them were a review of options to promote women and people of color to key positions and changes in training at the state police academy to rely less on "paramilitary training" and more on what were described as more modern policing skills, including de-escalation, the officials said at the time.