A former Alabama Department of Corrections sergeant pleaded guilty Tuesday to assaulting to handcuffed inmates at an Elmore prison, the Montgomery U.S. attorney’s office said.

Sgt. Ulysses Oliver, 44, faces up to 20 years in prison when he is sentenced.

The inmates were in an observation room at Elmore Correctional Facility when Oliver pulled one of the victim’s into a nearby hallway and struck him multiple times with his fists and feet before hitting the inmate with his collapsible baton 19 times, prosecutors said, citing Oliver’s guilty plea.

The second victim was then pulled into the hallway, where Oliver kicked him and hit him with a baton 10 times.

Oliver then brought both victims back to the observation room, where he shoved the tip of his baton into the face of one of the victims, leaving a laceration.

Both inmates were handcuffed and were not resisting or posing a threat, prosecutors said.

“Correctional officers have an incredibly difficult job,” U.S. Attorney Louis V. Franklin Sr. of the Middle District of Alabama said in a statement. “Although a vast majority of them serve with honor, valor, and bravery, cases like this make their jobs more challenging and dangerous. When officers abandon their oath to protect and serve, and engage in conduct that is criminal, they too must be held accountable. This office is committed to prosecute anyone who violates the law."

Prosecutors said Oliver filed false reports of the beatings, saying he only struck the victims on the legs when he in fact assaulted them with the baton all over their bodies. He also wrote that he hit the inmates until another officer told him to stop “when in truth the other officer had not ordered Oliver to stop,” according to the statement.

“Conduct like that of Mr. Oliver will not be tolerated and the Department of Corrections will work with all of its law enforcement partners to ensure that such behavior is thoroughly investigated and appropriately prosecuted,” said Alabama Commissioner of Corrections Jefferson S. Dunn.