Three Florida correctional officers were ordered to be held without bond on Friday after they were charged with murder in the beating death of a inmate housed in a mental health unit two months ago while he was being taken to another prison.

Miami-Dade Circuit Judge Mindy Glazer found probable cause to hold Christopher Rolon, 29, Kirk Walton, 34, and Ronald Connor, 24, in jail on charges of second-degree murder, conspiracy, aggravated battery of a disabled adult and cruel treatment of a detainee.

"We're looking forward to establishing his innocence when we go to court," attorney David Donet, who represents Walton, told a local NBC affiliate after the hearing.

A fourth officer, Jeremy Godbolt, 29, was taken into custody on Friday, Miami-Dade State Attorney Katherine Fernandez Rundle said during a news conference.

The correctional officers are accused of beating to death Ronald Gene Ingram, 60, on Feb. 14 at the Dade County Correctional Institution, she said.

"Individuals who are sentenced to incarceration by our criminal courts have lost their freedom but not their basic rights. They should not be subject to forms of back alley justice," Fernandez Rundle said.

Ingram, who was serving life for first-degree murder, was being held in cell in a mental health unit when officers arrived to take him to a prison in Lake County, about 300 miles (482 km) north. Before he was removed from his cell, Ingram threw urine at one of the officers, she said.

The officers handcuffed Ingram and removed him from his cell without any further incident. They then beat Ingram and carried him to a transport van where they placed him in a secure compartment by himself, she said.

During a stop in Ocala, Ingram was found deceased, lying on a bench inside the van. The inmate died as the result of a punctured lung and sustained injuries to his face and torso, Fernandez Rundle said, citing a medical examiner report.