Blunt trauma of the chest is known to be lethal due to the presence of vital organs inside the chest wall. A young man, who was arrested on June 24, 2020, at 11.00 pm due to sexual assault in a detention center in Pasuruan, was found dead the following day at 7.00 am. This prisoner was allegedly tortured and killed by other prisoners. Visum et Repertum was requested at the Department of Forensics, Bhayangkara Porong Hospital for external examination and autopsy. Bruises were found in the left and right side of the chest, in the upper extremities, in the back, and lower extremities from external examination. There were multiple fractures on the 6th, 7th, and 8th ribs found from the autopsy, and 500cc of blood was found in the left pleural space. The medical forensic approach is essential to determine the cause of death in this case.