Prosecutors say 33-year-old Spc. Neftaly Platero of Kingwood, Texas, grabbed his gun and shot the other three soldiers during an argument while they were deployed in the Iraqi city of Fallujah.
He was scheduled to be arraigned Monday before a military judge on charges of premeditated murder and attempted premeditated murder.
The shootings killed 26-year-old Pfc. Gebrah Noonan of Watertown, Conn., and 20-year-old Spc. John Carrillo Jr. of Stockton, Calif.
The Army has released few details about the Sept. 23, 2010 shootings, including the name of the wounded soldier.
The soldiers' unit returned to the Georgia Army post during the summer.