Washington (CNN) -- Ten Mexican nationals have been charged with last year's killings of three Americans connected to the U.S. Consulate in Juarez, Mexico, U.S. Attorney General Eric Holder announced Wednesday.
The 10 are among 35 members of the international gang Barrio Azteca charged with various counts of racketeering, murder, drug offenses, money laundering and obstruction of justice, Holder said.
"Twelve of these defendants were arrested just this morning by teams of United States federal, state and local authorities in Texas and in New Mexico," Holder announced at a Justice Department news conference.
U.S. Consulate employee Leslie Ann Enriquez Catton; her husband, Arthur Redelfs; and Jorge Alberto Salcido Ceniceros, the husband of another U.S. Consulate employee, were killed last March 13. Justice officials do not have a motive in the shootings, but they haven't ruled out a case of mistaken identity.
Seven of the 10 defendants charged with the consulate killings are in custody in Mexico, U.S. authorities said.
"The indictment unsealed today represents our continued action to ensure safety along our Southwest border, to seek justice for victims of violent crime in this region, and to weaken dangerous criminal organizations currently operating in Mexico and the United States," said Holder.
"These arrests and criminal charges will disrupt Barrio Azteca's current operations, and they reaffirm that we will not tolerate acts of violence against those who serve and protect American citizens. We will continue to stand with our partners in Mexico, and together, build on our unprecedented joint efforts to combat violence and protect the safety of the American and the Mexican people."
Justice officials say Barrio Azteca, which began in the late 1980s as a violent prison gang and expanded into a transnational criminal organization, is a highly organized and brutal gang.
"Barrio Azteca gang members are cold blooded criminals who show no respect for the law or justice, murdering innocent victims, trafficking drugs and inciting violence," said DEA Administrator Michele Leonhart.
"The fight is not over, we are in this for the long haul. We will continue to use every tool at our disposal to hold accountable violent criminal organizations and gangs that have been terrorizing border communities," said Assistant Attorney General Lanny A. Breuer of the Criminal Division.
"This is at times a gruesome battle, but make no mistake, we will not stop and we are not going away," Breuer added.
Holder said the Justice Department is working on extradition proceedings for the seven charged in the consulate killings and already in custody.