Fort Hood, Texas ? The alleged ringleader of the Abu Ghraib prison scandal went on trial Monday with witnesses telling a military court they watched him punch an Iraqi inmate in the face and saw him laugh while forcing prisoners to pose naked.

Spc. Charles Graner Jr. is the first soldier accused in the scandal to go on trial. His case is an important test of an argument put forth by defense attorneys that the soldiers were ordered to soften up detainees for interrogators and had no choice but to obey.

A military guard testified Monday that he saw Graner punch an Iraqi detainee in the face a moment after a notorious photo was taken at Abu Ghraib prison.

Another witness said Graner was “laughing and having a good time” while making naked prisoners pose.

Spc. Matthew Wisdom, the first witness in Graner’s prisoner abuse court-martial, said Graner was among a number of guards who roughed up detainees on Nov. 7, 2003.

Wisdom described a prominent photo from Abu Ghraib that showed the muscular Graner holding a prisoner as if he were about to strike him in the face.

Wisdom said he was urged to participate in abuse, but that he instead reported it to his immediate superior.

“I was very upset,” he said. “It made me kind of sick, almost. It didn’t seem right.”