U.S. Soldier Reportedly Described Rape Scene

At one point, two soldiers from the unit were killed at a checkpoint when an Iraqi man came up as if he wanted to shake hands and shot them, Watt said.

"I watched two guys I cared a lot about die right in front of me," he said, adding, "I was going to get a memorial tattoo of all the guys [killed], but there's not enough room on my arm."

Watt added that he was worried for his own safety when he learned about the alleged attack on the Iraqi family.

"It's like this: I find out that guys in my squad, guys I trusted with my life, are allegedly responsible for one of the most brutal rape-murders I've ever seen. And everyone has a weapon and grenades," he testified.

The U.S. military has charged four soldiers from the unit -- Barker, Cortez, Howard and Pfc. Jesse V. Spielman, -- with rape and murder.

Yribe was charged with dereliction of duty and making a false statement for allegedly failing to report the incident.

During the hearing, Special Agent Michael Hood, a trained polygraph administrator, testified that Spielman passed a lie-detector test when he said he did not kill or have sex with anyone in the house.

Army investigators said that the attack took about 20 minutes and that the killings were carried out with an AK-47 taken from the family's home. Defense attorneys appear to be building the case that the harsh conditions in Iraq and combat stress played a role in the attack.