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Inmates at the Mule Creek State Prison crowd between bunk beds in a gymnasium that was modified to house prisoners in Ione, California. The Mule Creek State Prison has had to modify several facilities to make room for an increasing number of inmates.

California must cut its prison population by forty thousand inmates following a US Supreme Court decision today. The 5 to 4 ruling upholds a lower federal court order to sharply reduce the number of prisoners in the state's system. The move is designed to tackle long term medical and mental health issues among those incarcerated. KPCC's Julie Small explains more.