A federal judge on Tuesday sentenced a former Mamou police chief to prison and accepted a guilty plea from his successor in a criminal civil rights investigation into their use of stun guns on inmates at the town’s jail.

U.S. District Judge Richard Haik sentenced former Mamou Police Chief Gregory W. Dupuis, 57, to one year and one day in prison for using stun guns to discipline “non-resistant” inmates, the U.S. Attorney’s Office announced in a news release.

Former Mamou Police Chief Robert McGee, 44, awaits a sentencing date after he pleaded guilty on Tuesday to the same allegations, which happened while he worked for Dupuis in 2010. McGee, who resigned last week, faces up to 10 years in prison, three years supervised release and a $250,000 fine.

Mamou’s aldermen have 20 days from McGee’s resignation to appoint an interim.

Both cases were under seal and not made public until Tuesday. Dupuis pleaded guilty on April 13.

Prosecutors said Dupuis, who served as chief from 1994-1997 and again from 2004-2014, routinely used the stun guns on inmates — including on those who appeared calm and compliant.

In one instance cited by prosecutors, Dupuis told an inmate who was only being verbally disruptive to get out of his bunk and put his hands on the wall. The inmate complied, and Dupuis then entered the jail cell and fired the stun gun at the inmate’s back, causing him to fall to the ground and injure his knee.

Prosecutors said in another instance involving McGee, he fired the stun gun at an inmate while having a verbal exchange with him.

Both incidents happened in 2010.

Through his personal Facebook account, McGee on Oct. 8 announced his resignation, alluding to a recent interview with the FBI about an incident five years ago.

“I made a mistake, which not only hurts my community but also hurts me dearly. I never intended to hurt anyone and was simply doing what I thought was right at the time,” McGee wrote.

A video surfaced days before McGee won the December runoff election showing him and another officer, who has since died, repeatedly using a stun gun on multiple inmates. The videos are from 2010.

Advocate staff writer Richard Burgess contributed to this article. Follow Lanie Lee Cook on Twitter, @lanieleecook, or contact her by phone at (337) 534-0825.