Three other soldiers in the unit - Sgt. John E. Hatley, Sgt. 1st Class Joseph P. Mayo, and Sgt. Michael P. Leahy Jr. - were charged Tuesday with premeditated murder, conspiracy to commit premeditated murder and obstruction of justice. They face a hearing to determine if there is enough evidence for them to be sent before a court-martial, but no date has been set.
Ramos and Spc. Steven Ribordy, 25, waived their rights to the Article 32 hearing, the equivalent to a civilian preliminary hearing.
An Army statement released on Friday said the court-martial represented only an accusation against Ramos and Ribordy. A date for Ribordy's court-martial has not been set.
"The accused soldiers are presumed innocent until and unless proven guilty," the statement said.
In an earlier statement, the Army said the allegations related to "the deaths of several detainees who were captured as part of combat operations last year."
That statement, released in January, said that "preliminary findings indicate the deceased detainees were not persons detained in a detention facility," indicating the men were killed shortly after being captured.
In hearings in late August, soldiers who were on the patrol said the four Iraqis who were killed, probably Sunnis, were taken into custody following a shootout with insurgents, and taken to the unit's operating base near Baghdad.
Hatley and Leahy were also charged with one count each of premeditated murder and conspiracy to commit premeditated murder in connection with a death near Baghdad in January 2007. Leahy was also charged with being an accessory after the fact, a statement this week from the military said.
The Army did not provide details on that death.