(CNN) -- A Texas judge sentenced a Mexican drug gang leader to life in prison Thursday after he pleaded guilty to murder and weapons charges related to the killing of a U.S. consulate employee and her husband, officials said.
Jose Antonio Acosta Hernandez, 34, also pleaded guilty to racketeering, drug trafficking and money laundering charges at his trial in El Paso, Texas, the U.S. Department of Justice said in a statement.
The authorities said Acosta, who is also known as "El Diego," admitted that he had directed or participated in more than 1,500 murders since 2008, when he became the leader of La Linea -- the enforcement arm of the Juarez cartel -- and a local boss for the cartel in the Mexican cities of Juarez and Chihuahua.
Among the killings that occurred under his watch was the shooting on March 13, 2010, of U.S. consulate employee Lesley Enriquez , who was gunned down with her husband, Arthur Redelfs, in Ciudad Juarez as they left a birthday party in their white SUV.
Jorge Salcido Ceniceros, the husband of another consulate employee, was killed in a separate vehicle.
"We are determined to hold accountable those individuals who committed the consulate murders, and to dismantle the dangerous criminal enterprise that fueled these and many other tragic and senseless acts of violence," Assistant Attorney General Lanny A. Breuer said in the Justice Department statement Thursday, accusing Acosta of directing a "reign of terror."
The Mexican authorities had listed him among their most wanted criminals and offered a 15 million peso reward for information leading to his arrest. They announced his capture last July.
He was extradited to the United States from Mexico last month, the Justice Department said.
Officials said Thursday that law enforcement agents in Mexico and the United States played a key role in the investigation.
"Gangs and other criminal organizations that threaten public safety on both sides of the border are on notice that we are working more closely than ever with our Mexican counterparts to shut them down," Breuer said.
The Mexican authorities have arrested several other people who they accuse of being connected to the consulate killings.
Acosta pleaded guilty Thursday to four counts of racketeering, narcotics trafficking and money laundering. He also pleaded guilty to seven counts of murder and weapons charges "specifically related" to the consulate killings, the Justice Department said.
Olga Bashbush, spokeswoman for the U.S. consulate in Ciudad Juarez, declined to comment on Acosta's guilty plea.
CNN's Nick Valencia contributed to this report.