cases with a grisly flourish like a beheading, and all from the comfort of his quiet home in the Paseos del Bosque neighborhood of Juarez. But the question was, where did the recordings come from?

The answer came on Feb. 11, when the prosecution called to the stand a confidential informant for the Drug Enforcement Agency (DEA) known only by the initials EQ. El Diario de Juarez described him as a man wearing a toupee of long straight gray hair, a full beard of the same color, and black tortoise-shell eyeglasses with a weak prescription.

EQ is a telecommunications specialist from Mexico. He was contacted about setting up a communications network by an old friend of his named Jaime Bon Arreola, who took orders from Gallegos. EQ put together atelecommunications network for the Juarez Cartel that went live in May 2010. The idea behind it was simple. The cartel had two groups of enforcers. The first was La Linea, a shadowy network of city and state police officers who moonlighted as an elite guard of hitmen, in many cases committing the crimes they would later be called to investigate. The other was Barrio Azteca, a gang whose members served as rank-and-file soldiers in the war against the Sinaloa Cartel. EQ’s network was built for the two groups to communicate with each other beyond the detection of scanners.

EQ used state-of-the art radio technology more advanced than anything even the DEA had available to counter it. To ensure adequate range, he planted a network antenna on top of Cerro