As an 18-year-old soldier in the Chilean Army in 1973, Mr. Padilla was on patrol with his unit in a southern city when the owner of a supermarket turned in his own son, accusing him of supplying munitions and food to a guerrilla group. The soldiers threw the young man into a well and began shooting at him. Then they dragged out his bloody, bullet-riddled body, put it in a military truck and drove off. Mr. Padilla was watching from a nearby jeep.
“I never knew where he was taken, and not even his name,” he said.