Updated at 1:59 p.m. ET:
According to the latest Associated Press report, a military prosecutor is accusing a Marine sergeant of making fatal assumptions and losing control of himself when he and his squad killed 24 Iraqis, including unarmed women and children, in the town of Haditha.
"The evidence will show that none of the victims were a threat," Maj. Nicholas Gannon told jurors in his opening statements on Monday, AP reported.
Prosecutors told the jury of four officers and four enlisted Marines that Staff Sgt. Frank Wuterich shot and did not ask questions.
Gannon said the sergeant also stood at the foot of a bed in a back bedroom, spraying a woman and children with bullets, AP reported.
Wuterich is charged with voluntary manslaughter in nine of the deaths and with other crimes. He is the last of the eight Marines initially accused of murder or failure to investigate the killings to face trial.
Six had charges dropped or dismissed, and one was acquitted.
Opening statements are set to be delivered Monday at Camp Pendleton in the trial of the last defendant in the biggest and longest criminal case against U.S. troops to arise from the Iraq war.
Wuterich has said he regretted the loss of civilian lives but believed he was operating within military combat rules.
Wuterich's lawyer says the 31-year-old Marine is confident the all-military jury will acquit him.
The massacre further tainted America's reputation when it was already at a low point after the release of photos of prisoner abuse by U.S. soldiers at Abu Ghraib prison.
Check back for further developments.
The Associated Press contributed to this report.