In January 1945, Mucci led 128 Army Rangers in liberating the Cabanatuan Prison Camp with the loss of only 2 men killed in action. Mucci refused to sit back on the mission and joined his soldiers on the ground in combat, an unusual position for a colonel. The raid was supported by some 250 Filipino guerrillas, many of whom were unarmed, who guided the Rangers through Japanese held territory and held off Japanese reinforcements while the American Rangers freed the POWs.