Lima, Peru (CNN) -- An elderly man's brain languishes. His body languishes, too, in prison. No one seems to know he's there. Before a sudden turn of events this month, this was the story of Juan Navarro, who spent nearly 37 years inside the tough San Pedro prison in the Lima neighborhood of San Juan de Lurigancho. To be precise, before being released this week, Navarro spent 36 years and eight months in prison. The exactness of this number is important because it is one of the few facts that he has certainty about. He doesn't know how old he is. He doesn't remember if he ever appeared before a judge. He can't recall if he was convicted.
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Juan Navarro was in a Peruvian prison for nearly 37 years
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But neither he nor officials know whether he was ever sentenced
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He languished in prison longer than the maximum sentence
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The government ensured his release this week
At some point he was transferred to the prison in @placeholder, but his file remained stored in the province where he was arrested.