Pvt. Zachary Thomas, who was on the patrol on July 2, 2012, said 1st Lt. Clint Lorance's first words to another soldier who reported seeing a motorcycle were "Why aren't you shooting yet?"
Spc. James Twist testified that on the first day Lorance arrived at his unit's outpost in southern Afghanistan's Kandahar Province, an Afghan with a small child approached them at the gate. The Afghan asked if he could move concertina wire a few feet so that he could access his fields, Twist said Tuesday.
Twist said Lorance told the Afghan one of his soldiers would shoot him if he touched the wire.
Lorance is charged with murder, attempted murder, making false statements, ordering soldiers to wrongfully discharge their firearms and impeding the investigation. His court-martial opened Tuesday, and he faces life in prison if convicted.
Guy Womack, who represents Lorance, stressed that Taliban soldiers don't wear uniforms, making it hard to differentiate them from civilians. Womack said men on motorcycles were known to often be part of enemy forces.
Prosecutors say Lorance ordered his men to open fire immediately in violation of the military's rules of engagement, which requires soldiers to hold fire unless they have evidence of hostile action or hostile intent.
Lorance's family maintains he did what he had to do to keep his troops safe.
"He's a very strong, courageous young man. He's very strong. He still believes it what he's done," said Anna Lorance, Clint's mother. "He believes he's done what he should have. He believes he's done everything he could do, and he's leaning on that and trusting in that to get him through."
According to prosecutors, three men on a motorcycle approached the patrol last July. Two were killed and the third ran away.
The case is expected to wrap up later this week.