The Iranian authorities must immediately allow independent international monitors unhindered access to Iranian prisons to investigate the harrowing use of unlawful force by security forces at Tehran’s Evin prison on 15 October 2022 and to protect prisoners from further unlawful killings, torture and other ill-treatment. This latest deadly incident once again brings into sharp focus the urgent need to address the litany of crimes being committed by the Iranian authorities through an independent investigative, reporting and accountability mechanism.