Assassination
After the arrest, Nhung and Nghĩa sat with the brothers in the APC, and the convoy departed for Tân Sơn Nhứt. Before the convoy had departed for the church, Minh was reported to have gestured to Nhung with two fingers. This was taken to be an order to kill both brothers. The convoy stopped at a railroad crossing on the return trip, where by all accounts the brothers were assassinated. An investigation by Đôn determined that Nghĩa had shot the brothers at point-blank range with a semi-automatic firearm and that Nhung sprayed them with bullets before repeatedly stabbing the bodies with a knife.
Nghĩa gave his account of what occurred during the journey back to the military headquarters: "As we rode back to the Joint General Staff headquarters, Diệm sat silently, but Nhu and the captain began to insult each other. I don't know who started it. The name-calling grew passionate. The captain had hated Nhu before. Now he was charged with emotion." Nghĩa said that when the convoy reached a train crossing, " lunged at Nhu with a bayonet and stabbed him again and again, maybe fifteen or twenty times. Still in a rage, he turned to Diệm, took out his revolver and shot him in the head. Then he looked back at Nhu, who was lying on the floor, twitching. He put a bullet into his head too. Neither Diệm nor Nhu ever defended themselves. Their hands were tied."
Read more about this topic: Arrest And Assassination Of Ngo Dinh Diem