The alleged leader of US troops who killed 24 unarmed Iraqi civilians in 2005 in Haditha will not face murder charges, a US Marines spokesman said.
Sgt Wuterich says he was operating within military combat rules
Sgt Frank Wuterich, 27, will stand trial for voluntary manslaughter, aggravated assault, dereliction of duty and other charges, officials said.
The decision was made by Lt Gen Samuel Helland, who is overseeing the case.
Sgt Wuterich is the last of four marines to have the murder charge against him dropped.
Another marine, 1st Lt Andrew Grayson, was ordered to face court-martial for making false official statements and other charges.
Twenty-four Iraqi civilians, including three women, seven children and several elderly men, died at Haditha, in Anbar province, on 19 November 2005.
Iraqi witnesses say the shootings were in retaliation for a roadside bomb that killed one of the marines, Lance Cpl Miguel Terrazas, as his convoy drove through the town.
The US military at first reported that the Iraqis had been killed by an improvised explosive device (IED) that killed L/Cpl Terrazas, or in a subsequent gunfight with insurgents.
But Iraqi witnesses said the US troops shot dead five unarmed men in a car when they approached the scene of the bombing in a taxi.
They were then accused of killing 19 other civilians in three houses nearby over the next few hours.
Despite the accusations, there was no full US investigation into what happened until January 2006, when video footage emerged of the aftermath, shot by a local human rights activist.