IRVINE, Calif. (AP) _ A former Marine sergeant facing the first federal civilian prosecution of a military member accused of a war crime says there is much more at stake than his claim of innocence on charges that he killed unarmed detainees in Fallujah, Iraq.

In the view of Jose Luis Nazario Jr., U.S. troops may begin to question whether they will be prosecuted by civilians for doing what their military superiors taught them to do in battle.

Nazario is the first military service member who has completed his duty to be brought to trial under a law that allows the government to prosecute defense contractors, military dependents and those no longer in the military who commit crimes outside the United States.

"They train us, and they expect us to rely back on that training. Then when we use that training, they prosecute us for it?" Nazario said during an interview Saturday with The Associated Press.

If Nazario, 28, is convicted of voluntary manslaughter, some predict damaging consequences on the battlefield.

"This boils down to one thing in my mind: Are we going to allow civilian juries to Monday-morning-quarterback military decisions?" said Nazario's attorney, Kevin McDermott.

Others say the law closes a loophole that allowed former military service members to slip beyond the reach of prosecution. Once they complete their terms, troops cannot be prosecuted in military court.

The complaint states the squad had been taking fire from the house. After the troops entered the building and captured the insurgents, Nazario placed a call on his radio.

"Nazario said that he was asked, 'Are they dead yet?'" the complaint states. When Nazario responded that that the captives were still alive, he was allegedly told by the Marine on the radio to "make it happen."

Even discharged service members can be recalled to active duty in order to stand court martial