FT. BRAGG, N.C. — The leader of an Army special forces team grinned as he held the severed ear of an Afghan man he suspected of being an insurgent after he shot him and left his body in the desert, a Green Beret testified Tuesday.

The testimony by Sgt. 1st Class Ricky Derring came at a military hearing for his team leader, Master Sgt. Joseph D. Newell, 38, from Tecumseh, Mich. Newell, who has been in the military for two decades, could face court martial on a murder charge in the March 5 killing of the Afghan civilian.

Derring said Newell returned to the spot where he left the man’s body and “made a stabbing motion and I could see his arms cutting.” Newell then walked back to the team’s vehicle with the man’s ear in his hand, Derring said.

“He shook the ear and grinned,” Derring said.

Under cross examination by Newell’s civilian attorney Todd Conormon, Derring said he didn’t actually see Newell cut off the man’s ear.

The Article 32 hearing that is expected to last two days is similar to a civilian grand jury. It is not used to decide guilt, only whether there’s enough evidence to court martial Newell, who was assigned to the Ft. Bragg-based 3rd Special Forces Group. The Army hasn’t released details about Newell such as his age, hometown and how long he has served.

Derring said his team was escorting a convoy of supplies in Helmand province, when they saw two civilian cars in the distance. The soldiers fired a warning shot and went to investigate.

Derring, a 50-caliber machine gunner on the team, said Newell asked the man through an interpreter whether he was an insurgent or had improvised explosive devices. He questioned him about a photo of a weapon on his cell phone.

“Joe was asking him questions: Where did he get the phone, was he placing IEDs, was he Taliban,” Derring testified during a hearing at Ft. Bragg, an Army base near Fayetteville.

Derring said the man answered no. But Derring said he, Newell and the interpreter believed the man was an insurgent because Taliban forces often use cell phones to communicate and call in their locations.

Newell drew his gun and shot him, left him in the desert, then returned and cut off his ear, Derring testified. Newell took the body to another place in the desert, “and kicked sand over his face a little bit,” Derring said.

Derring responded to Conormon’s questions about hard feelings between Newell and other team members. Derring said they would argue about tactics and other matters, adding that Newell had to assert himself because he was a newer member of the team.

Derring said he was upset about the shooting and later told another sergeant what had happened.

“He basically said Master Sgt. Newell had a screw loose,” Derring said.

Newell later talked to Derring about the killing, during which Derring told Newell he never wanted to be in that kind of situation, Derring said.

“He told me, ‘Don’t worry, nothing will come of it.’ He said, ‘If it does, I’ll just say I was attacked,’” Derring testified.