When Army investigators tried to interrogate Staff Sgt. Calvin R. Gibbs in May about the suspected murders of three Afghan civilians, he declined to answer questions. But as he was being fingerprinted, Gibbs lifted up his pant leg to reveal a tattoo.
Engraved on his left calf was a picture of a crossed pair of pistols, framed by six skulls. The tattoo was "his way of keeping count of the kills he had," according to a report filed by a special agent for the Army's Criminal Investigations Command. Three of the skulls, colored in red, represented kills in Iraq, Gibbs told the agent; the others, in blue, were from Afghanistan.