Gallegos, 35, was a lieutenant in a cross-border gang known as Barrio Azteca, or Los Aztecas. U.S. officials said he ordered the deaths of hundreds as drug cartels battled each other over control of Ciudad Juárez, on the U.S.-Mexico border. He was convicted of murder, drug trafficking and money laundering in U.S. federal court in February.
The Mexico City trial involved killings Gallegos ordered on consular employees and their families in what appeared to be cases of mistaken identity. Lesley Enriquez, 35, a consular worker who was pregnant, and her husband Arthur Redelfs, 34, were killed in 2010 while driving in a white SUV. Jorge Albert Salcido Ceniceros, 37, the husband of another consular worker, was also killed while driving in a white SUV. At the trial, witnesses said Gallegos had ordered the murders because the vehicles were similar to those used by a rival drug gang.
Judge Kathleen Cardone also ordered Gallegos to pay nearly $1 million to families of the victims.
Over 20 other people have been convicted in trials that grew from the investigation of the case, federal prosecutors said.