SEATTLE: Military prosecutors on Tuesday charged a sixth US soldier with direct involvement in the murder of unarmed Afghan civilians, implicating a sergeant who was referred earlier for court-martial on lesser offenses.

It marked the first time since the spring of 2010 that the Army has formally brought new charges in the most serious prosecution of alleged US military atrocities in nearly 10 years of war in Afghanistan.

Staff Sergeant David Bram, 27, was newly charged with a single count each of solicitation to commit premeditated murder, of failure to report crimes including murder, and of planting evidence near the body of an Afghan national.

He also is charged with unlawfully engaging in “murder scenario conversations” with subordinates and with aggravated assault with a dangerous weapon on Afghan civilians.

Bram remains free from pretrial confinement, said Major Kathleen Turner, a spokeswoman for Joint Base Lewis-McChord, the home Army installation of Bram and his co-defendants near Tacoma, Washington.

Bram was ordered last year to stand trial on five other charges, the most serious of which accused him of plotting and taking part in the beating of another US soldier who some troops feared might tell investigators about hashish use.

If convicted of all 10 charges against him, Bram, of Vacaville, California, could be sentenced to as much as 21 years in prison, the Army said.

Five other members of the infantry unit formerly called the 5th Stryker Brigade have been charged with premeditated murder in connection with three Afghan civilian slayings that investigators say were staged to look like legitimate combat casualties.

One of those soldiers, Specialist Jeremy Morlock, was sentenced in March to 24 years in prison after he pleaded guilty to three counts of murder, agreed to testify against his co-defendants and apologized in court, saying, “I lost my moral compass.”

Seven others, including Bram, were charged with lesser offenses.