CAMP PENDLETON --- Eight Marine Corps officers are weighing the fate of a sergeant accused of killing an Iraqi insurgent prisoner of war in what a prosecutor acknowledged is a "tough case."

The panel is deciding whether 26-year-old Sgt. Ryan Weemer committed murder, as the prosecution alleges, or acted in self-defense, as the Illinois native's attorney contends.

At minimum, prosecutor Capt. Nicholas Gannon told jurors Wednesday that Weemer is guilty of voluntary manslaughter in the 2004 incident that occurred in the opening hours of an intense, door-to-door fight for the Anbar province city of Fallujah.

Gannon stressed that two statements Weemer made to investigators in 2006 contain no mention of self-defense. Weemer's attorney, Paul Hackett, argued that self-defense is what drove his client's actions inside a Fallujah home on the morning of Nov. 9.

"This case was about following the rules when it's really hard to follow the rules," Gannon told the jury. "But you need look no further than the two statements provided by the accused as evidence of his guilt."

Weemer is charged with unpremeditated murder and dereliction of duty and could face up to life in prison if convicted. Prosecutors allege he killed one of four captive insurgents slain that morning by members of a 3rd Battalion, 1st Marine Regiment Kilo Company squad.

Hackett said jurors have sufficient cause to believe Weemer acted in self-defense. He pointed to two witnesses who testified that Weemer told them the prisoner had "lunged" for his gun, prompting him to shoot the man in the chest.

"This was not the neighbors in the house next door," Hackett said of the men the Marines confronted in Fallujah that day. "These guys were there to kill Marines."

But Gannon emphasized that in his statements to investigators, Weemer made incriminating statements about killing one of the captives with no mention of self-defense.

"You can hear the regret, you can hear the remorse because he knew what he did on November 9th was wrong," Gannon said as Weemer sat expressionless at the defense table taking occasional notes.

Hackett rejected Gannon's intimation that Weemer killed the man as vengeance for his best friend, Lance Cpl. Juan Segura, being killed earlier that day by a sniper's bullet.

Instead, he said, Weemer and the man he is accused of killing were in a struggle when his client shot him.

"Nobody really knows what the hell happened here," Hackett said. "But it wasn't murder, it wasn't a vengeful killing."

Hackett urged the jurors to give Weemer, a man numerous witnesses testified was an upstanding, well-trained Marine, the "benefit of the doubt" and acquit him on all charges.

Weemer's squad leader in Fallujah, former Marine Sgt. Jose L. Nazario Jr., was tried and acquitted last year on charges he killed two of the prisoners. A third man, Sgt. Jermaine Nelson, faces trial at Camp Pendleton later this year.

Weemer did not testify and the defense called only a handful of witnesses who testified they considered him well-spoken, knowledgeable and respectful.

The case emerged when Weemer, who had left the service, told a Secret Service job interviewer about the incident. He was then recalled to active duty and charges were filed.

Throughout the trial, Weemer's wife, sister and high school English teacher have sat directly behind him. His sister wears a bracelet imprinted with her brother's name.

Six of the jurors must agree in order to convict him on any of the charges.

The panel of combat-experienced officers deliberated for nearly five hours Wednesday before retiring for the night shortly before 9 p.m. They are scheduled to resume their work at 8 a.m. Thursday.

Bing West, author of a book about the Iraq war that chronicles Weemer being wounded four days after the alleged prisoner slayings, said it's a sad case for all involved.

"No matter how you look at it, it's a tragedy," West said in a telephone interview. "We have tightened up our moral standards to such a degree that I don't know how the 'Greatest Generation' would have fared if they were put under the microscope like this," he said in reference to World War II service members.

But Gary Solis, a military law expert and former Marine Corps judge, said the case had to be brought before a jury.

"When an alleged war crime comes to light, the military cannot ignore it lest it be charged with condoning a war crime," he said.

Contact staff writer Mark Walker at (760) 740-3529 or mlwalker@nctimes.com.