Army prosecutors have dropped one of the 17 murder charges against Staff Sgt. Robert Bales for his alleged shooting rampage against Afghan civilians this past March.
Prosecutors also have added charges that he used alcohol and steroids during his deployment to Afghanistan.
During the pre-dawn hours of March 11, Bales is alleged to have snuck out of his remote combat outpost on two occasions to shoot Afghans in two villages close to his base in western Kandahar province.
Afghan and U.S. officials said at the time that 16 non-combatants were killed in the shooting rampage. However, when the criminal charges were filed, they alleged Bales was responsible for 17 counts of murder. Defense officials at the time said the criminal investigation had turned up evidence of a 17th victim.
An Army statement announcing the amended charges said the reduction in the number of murder charges "conform to developments in the ongoing investigation surrounding Staff Sgt. Bales' alleged crimes on March 11, 2012."
An Army official said a further investigation and review of the incident with Afghan authorities and the families of victims has determined there were 16 murder victims.
Bales is also charged with a single count of "wrongfully consuming alcoholic beverages within the country of Afghanistan," which matches reporting by ABC News and other outlets that Bales had used alcohol prior to the shooting incident.
In addition to the murder charges, Bales also faces six charges of attempted murder and a new seventh charge of assault. In addition, there are "two specifications of wrongfully possessing and using a Schedule III controlled substance [steroids]." The charge sheets identify the steroid as stanozolol.
Bales is currently being detained at a military prison at Fort Leavenworth, Kan.