ALTAMIRA, Brazil (Reuters) - Odijane Mota still cannot make sense of her son Efraim’s gruesome death in a Brazilian jail.

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The 22 year old was one of dozens of inmates killed during prison riots in the northern Brazilian city of Altamira last week, and she struggles to grapple with the death sentence meted out by fellow prisoners to her son. He was serving an eight-year sentence for stealing a cellphone while riding a stolen motorcycle.

“When I think of the way my son died, I’m overcome by sadness, by anguish,” she told Reuters from behind sunglasses that masked her tear-swollen eyes. “My son didn’t go there to die, you know. He didn’t go there to die.”

At least 58 prisoners died during a chaotic few hours of violence in the prison in the northern state of Para last week. More than a dozen were decapitated, and videos circulating online showed inmates at the prison celebrating as they kicked heads across the floor.

State authorities said the riot began around breakfast time on Monday, when prisoners belonging to the Comando Classe A gang set fire to a cell containing inmates from rival gang Comando Vermelho, or Red Command.

The violence was the latest in a series of deadly riots that have shone a spotlight on Brazil’s dangerous, overcrowded prison system, the world’s third largest.

Controlling the country’s prisons and taming their powerful prison gangs are major public security headaches for President Jair Bolsonaro, who campaigned on hard-line security proposals.

“My son was not a highly dangerous criminal,” said Mota, who Mblamed state authorities for not doing more to prevent the bloodshed in the jail once the fire broke out.

She vowed to fight for justice for her son, so that his death was not in vain.

“I’m never going to settle for it, never ever,” she said. “Knowing that nobody did anything, that will be a sad thing that I will carry for the rest of my life with hatred in my heart. They had a chance to do it, they had time to do it and nobody did anything.”