The court-martial of Staff Sgt. David Bram of the U.S. Army's 5th Stryker Brigade, one of 12 soldiers accused in the attacks, was set to begin Wednesday.
Bram of Vacaville, Calif., is accused of being part of a group of rogue soldiers who allegedly plotted to kill civilians and then planted weapons on them, CNN reported
The killings took place over five months at or near Forward Operating Base Ramrod in southern Afghanistan.
Three soldiers have pleaded guilty to the killings and six were convicted of lesser crimes.
Bram is charged with conspiracy to commit assault and battery, unlawfully striking another soldier, violating a lawful order, dereliction of duty, cruelty and maltreament and endeavoring to impede an investigation, CNN said.