JACKSON (AP) — An inmate plans to plead guilty to participating in a deadly prison riot in Mississippi, federal court records say.

One guard was killed and 20 people were injured in the May 20 riot at the privately run Adams County Correctional Facility in Natchez, which houses illegal immigrants convicted of crimes in the U.S.

A filing Friday in U.S. District Court in Natchez says Yoany Oriel Serrano-Bejarano plans to change his plea to guilty.

A complaint filed by an FBI agent says he assaulted a guard and helped other inmates climb onto the roof of a building where correction officer Catlin Carithers was beaten to death.

“Serrano-Bejarano has been identified as one of the inmates who held the food carts so the inmates could access the roof,” according to the affidavit.

The court documents also say that Serrano-Bejarano assaulted a different guard, was seen with a prison guard’s radio and destroyed cameras and windows.

At least one other inmate has pleaded guilty in the case.

Juan Lopez-Fuentes pleaded guilty to participating in the riot during a hearing Aug. 27 in U.S. District Court in Natchez. Lopez-Fuentes was sentenced to more than three years.

Court records say the prisoners were angry about their treatment the day the riot erupted.

The prison holds approximately 2,500 illegal immigrants, most of them convicted on charges of coming back to the U.S. after being deported. The prison is owned by Nashville, Tenn.-based Corrections Corporation of America, one of the nation’s largest private prison companies.