Arellano Stark was one of the key officers involved in the September 11, 1973 coup that deposed democratically elected President Salvador Allende and led to the installment of Pinochet. After the coup, Arellano Stark handpicked a squad to spend two months going from town to town searching for dissidents under the military junta. Once the rebels were killed, their names were crossed off a list. The “Caravan of Death" was estimated to have killed 75 political prisoners. The helicopter squad surprised several commanders, who were not expecting it to brandish heavy firearms and instead were planning a grand parade. Soldiers were ordered to perform summary killings, and bodies were dumped in mine shafts or in the Atacama Desert.