Seconds after a roadside bomb exploded in Haditha and killed a Marine driving a Humvee, five men who were at the scene in a white car were shot to death by the dead Marine's squad mates.

Staff Sgt. Frank Wuterich has acknowledged shooting the men in the 2005 incident, but claims he did so because they were running away from the site of the blast. Combat rules at the time allowed Marines to shoot at people fleeing the scene of an attack.

Precisely how the men died was set to be scrutinized Wednesday, as a hearing resumes to determine whether Wuterich should stand trial for murder. He is charged with unpremeditated murder in the deaths of 17 Iraqis, including the five men, making his case the biggest to have emerged against a U.S. troop in Iraq.

In all, 24 civilians were killed by Wuterich's squad in the aftermath of the bomb blast on Nov. 19, 2005. Among the dead were women and children who were killed in their homes as Marines went on a house-to-house sweep.

The government is expected to call Naval Criminal Investigative Service Special Agent Tom Brady, a forensic expert who will offer his opinion about what happened to the five men.

Prosecutors are focusing on how the men died because they have a witness, Sgt. Sanick Dela Cruz, who claims the men were not running and had their hands in the air when he saw Wuterich shoot them.

Wuterich's lead civilian attorney, Neal Puckett, said Dela Cruz's account was false, and Brady's evaluation of the evidence would prove it.

Dela Cruz was initially charged with murdering the men, but the charges against him were dismissed and he was given immunity to testify against Wuterich.

"The version of events that Sergeant Dela Cruz gave will be directly contradicted by the government's forensic evidence," Puckett said.

Among the evidence assessed by Brady is video footage taken by an unmanned aerial drone about 45 minutes after the men were shot. The video shows five men lying in a cluster by a white car.

In all, four enlisted Marines were charged with murder and four officers were charged with dereliction of duty for failing to investigate the deaths. Charges have so far been dropped against three of the men.

The case centers on whether Wuterich, who had never experienced combat before, acted within Marine rules of engagement when he shot the men by the car and led the house raids.

Wuterich asserts that he was following combat rules in place at the time and that he attacked the houses because he thought gunfire was coming from them.

At the end of the hearing, investigating officer Lt. Col. Paul Ware is slated to make a recommendation about whether Wuterich should stand trial. Lt. Gen. James Mattis, the general overseeing the case, will make the final decision.

Ware has already presided over hearings for Lance Cpls. Stephen Tatum and Justin Sharratt, who were charged with murder. In both cases, Ware recommended the charges be dismissed. Mattis dismissed Sharratt's case; a decision on Tatum is pending.

Wuterich is also charged with making a false official statement and telling another Marine to do the same. He faces a possible life sentence and dishonorable discharge if court-martialed.