What can one say?

WaPo:

From inside a vacant building, Sgt. 1st Class Domingo Ruiz watched through a rifle scope as three cars stopped on the other side of the road. A man carrying a machine gun got out and began to transfer weapons into the trunk of one of the cars.

"Take him down," Ruiz told a sniper.

The sniper fired his powerful M-14 rifle and the man's head exploded, several American soldiers recalled. As he fell, more soldiers opened fire, killing at least one other insurgent. After the ambush, the Americans scooped up a piece of skull and took it back to their base as evidence of the successful mission.
...
Although Ruiz is not the highest-ranking soldier in the unit, his command over the 4th Platoon is absolute. Last fall, commanders transferred a platoon leader just 48 hours after he tangled with Ruiz.

When another young platoon leader, Lt. Colin Keating, 23, of Clinton, Md., arrived Feb. 6, Ruiz greeted him warmly and introduced him to every soldier in the platoon, but told him: "Just let me fight my war."
...
Ruiz said the decision to pick up the skull fragment and take it back to the base was a "sarcastic" gesture to confirm the kill to the battalion. [Capt. Rob] Born, who was not present during the attack, said the soldiers picked up the fragment not as a trophy, which is prohibited under military regulations, but to confirm "that we had the remains of a terrorist."