A US Army staff sergeant accused of leading a rogue \"kill squad\" charged with murdering three Afghan civilians took the stand Friday during his court martial and denied carrying out the killings. Yet he admitted to cutting off body parts as part of what prosecutors called a gruesome practice of keeping battlefield \"trophies.\" The CNN said Staff Sgt. Calvin Gibbs\'\' surprise testimony came a week after his court martial began. It is the first time Gibbs has publicly presented his version of what happened with the platoon he led from the Army\'\'s 5th Stryker Brigade. He is the highest-ranking soldier charged in what prosecutors say was a rogue \"kill squad\" that allegedly targeted Afghan civilians and made it look like they\'\'d been insurgents. Twelve soldiers have been charged in the case. Three have pleaded guilty to murders and agreed to testify against fellow soldiers. Another six have been convicted of lesser crimes.