The announcement comes amid an intensifying debate over the department's failed Fast and Furious anti-gunrunning operation. Weapons from that program were found at Terry's murder scene -- Republicans seeking documents pertaining to Fast and Furious last month escalated their probe by voting to hold Attorney General Eric Holder in contempt of Congress.
Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Reform Committee, praised the department Monday for its announcement but questioned the timing.
"Today's developments certainly mean that the criminal prosecution of Brian Terry's killers is moving forward," Terry family attorney Patrick McGroder said.
The 11-count indictment, originally handed up by a grand jury in November 2011, implicates five defendants in the killing. A sixth suspect has also been charged in a related incident.
The two men in custody are Manuel Osario Arellanes -- who was wounded in the foot the night of the firefight -- and his brother Rito. Rito, who was arrested two nights before the Terry shooting, allegedly helped provide weapons to the criminal gang used in the shooting. All six men named in the indictment are either related or friends.
The other four are believed to be hiding out in Mexico, and the U.S. is now offering a reward of up to $1 million for information leading to their arrest. They are: Jesus Rosario Favela-Astorga; Ivan Soto-Barraza; Heraclio Osorio-Arellanes; and Lionel Portillo-Meza.
According to the indictment, the five defendants are charged with crimes including first-degree murder, second-degree murder and assault on a federal officer. The indictment alleges that the five defendants also assaulted three other Border Patrol agents who were with Terry at the time.