JACKSON (AP) — A federal judge has ordered a man who faced deportation to remain behind bars in the U.S. on charges of participating in a deadly riot at a prison for illegal immigrants.

Juan Lopez-Fuentes is suspected of leading a group of inmates who took hostages at the Adams County Correctional Facility in Natchez during a May 20 riot. One guard was killed; at least 20 people were injured.

U.S. Magistrate Judge Linda Anderson in Jackson signed an order Friday to keep Lopez-Fuentes locked up pending the outcome of the case. Deportation proceedings for him had been set to begin later this month.

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

Anderson wrote in the order that Lopez-Fuentes was serving time for two previous felonies at the time of the riot. Her order says Lopez-Fuentes has few ties in Mississippi while most of his family is in Mexico, so there’s little to keep him from fleeing the country.

The prison holds nearly 2,500 illegal immigrants convicted of crimes in the United States. It’s owned by Nashville, Tenn.-based Corrections Corporation of America, one of the nation’s largest private prison companies.

An FBI agent’s affidavit in the case said the riot was started by a group of Mexican inmates, known as Paisas, who were angry about what they considered poor food and medical care and disrespectful guards. Paisas are a loosely affiliated group within the prison, without ties to organized gangs, FBI spokeswoman Deborah Madden said.

The FBI affidavit is part of a criminal complaint that alleges that Juan Lopez-Fuentes was in charge of a group of inmates who took hostages in one section of the prison. Lopez-Fuentes allegedly forced one of the hostages, a prison guard, to relay orders for tactical teams to drop their weapons and back off.

It took hours for authorities to control the riot, which grew to involve hundreds of inmates.

The prison’s special response team and the Mississippi Highway Patrol’s SWAT team worked to end the riot while state and area law enforcement officers, some from neighboring Louisiana, helped secure the outside, officials have said.

Before being charged with rioting, deportation procedures were to begin for Lopez-Fuentes this month.