A sixth correction officer has been arraigned on murder charges in connection with the death of Robert Brooks at Marcy Correctional Facility.

Nicholas Kieffer, 33, was charged with second-degree murder, first-degree manslaughter, second-degree gang assault and offering a false instrument for filing Monday morning in Oneida County Court. He pleaded not guilty to all charges.

Onondaga County Assistant District Attorney Jarrett Woodfork said the charges mean Kieffer played an active role in Brooks’s death.

“We are definitely taking the position that anyone that was charged with murder had a hands-on and active role in the assault and death of Mr. Brooks,” he said.

Kieffer is the tenth person arraigned in the December death of Brooks, an inmate at Marcy prison in Oneida County. He joins five other correctional officers who are facing the highest charge in this case – murder in the second degree. Five other prison workers were charged with second-degree murder on Thursday.

Nicholas Anzalone, David Kingsley, Anthony Farina, Christopher Walrath and Mathew Galliher — all former correction officers — are named in the indictment. They were also all charged with manslaughter in the first degree, the indictment says. They face a potential punishment of life in prison for those charges. All pleaded not guilty.

Kieffer was absent from last week's arraignments due to a scheduling conflict.

“It was some confusion about when he was supposed to turn himself in, and plans he had prior to that,” Woodfork said.

The charges stem from an incident at Marcy Correctional caught on body-worn cameras, triggering widespread outrage and calls for justice. Body camera footage released by the New York attorney general’s office shows correctional officers hitting Brooks while he was restrained at the prison on Dec. 9. He died the next day at a hospital in Utica.

An autopsy report issued by the county medical examiner’s office in January concluded that Brooks’ death was caused by compression of the neck and multiple blunt impact injuries and that the manner of death was determined to be a homicide, according to Brooks' family attorneys.

Woodfork said naming those involved in the case is a first step down a long road to justice.

“We have one job to do. Our job takes place no matter which courthouse we’re in. Seeking justice is the sole goal of our office,” he said.

Kieffer and the other nine prison workers charged in connection to the case are scheduled for a pretrial conference on March 31.