SALT LAKE CITY — A Utah State Prison inmate accused of killing his cellmate was charged with murder on Friday.

James Afuakimoana Tamoua, 24, of Salt Lake City, was charged in 3rd District Court with the first-degree felony in the death of Reo Guy Watts, 38, of Salem.

On Sept. 21, about 10 p.m. prison officials responded to a cell in the Oquirrh block after receiving an emergency call and found Watts unresponsive in his bed, according to charging documents. He was declared dead on scene, the charges state. The emergency call was initiated by an emergency button being pressed from the cell.

Tamoua, who was at the door of the cell when officials arrived, stated “I think I killed him” and “Cuff me up,” according to charging documents.

James Afuakimoana Tamoua | Utah State Prison

During a formal interview later, Tamoua said while Watts was in his bed, he flipped Watts onto his stomach and “put my arm around his neck, and I strangled him to death,” the charges state.

Charging documents do not give a possible motive for the seemingly unprovoked attack.

According to court records, Tamoua was charged with theft in 2017. But the case was delayed while he also faced federal charges.

In February, resolutions were reached on all of his cases. He was convicted in federal court of violating the Hobbs Act when he robbed a convenience store at gunpoint, according to court records. For that, he was sentenced to five years in prison.

He was also convicted on the state charge and sentenced to up to five years in the Utah State Prison.

While he was being held in the Davis County Jail awaiting trial on those charges, he stabbed another inmate multiple times with a pencil in October 2018, according to charging documents. He was convicted of attempted aggravated assault and sentenced to up to five years in prison.

He was also convicted of breaking the fire sprinkler in his cell while in Davis County Jail a couple of times, court records state.

Watts was serving time for a 2017 conviction of failing to stop for police and sentenced to up to five years in prison, according to court records.