Lazcano was an original member of the Zetas, which started out as a paramilitary hit squad for the Gulf cartel before breaking off to work independently, ultimately rising to become one of the most feared gangs in Mexico. Like most of the Zetas founding members, Lazcano was a former Mexican special forces soldier, and thus a cut above the average Mexican gangster. Lazcano has run the Zetas gang since 2004, and in his book "El Narco," journalist Ioan Grillo wrote that Lazcano brought the gang's violence to a new level after he took over, targeting not just victims and rival gangs, but authorities as well.
Taking leadership of the Zetas was Heriberto Lazcano, or Z-3, known by his chilling nickname the Executioner. Hailing from the rural state of Hidalgo, the muscular, thick-necked Lazcano shared a peasant background with his friend and mentor [Arturo] Guzmán, Z-1. Lazcano also joined the army as a teenager and gained promotion to the special forces. When Guzmán defected, the loyal Lazcano was quick to follow. However, Lazcano, who took control of the Zetas at age twenty-eight, proved he was more bloodthirsty than his teacher.
Guards at a penitentiary in Matamoros refused to smuggle in luxuries to some Zetas prisoners. So Lazcano applied pressure. One night, as six prison workers finished a late shift, waiting Zetas abducted them one by one. Hours later, a horrified guard at the prison gates found the bodies of the six employees in a Ford Explorer. They had been blindfolded, hand-cuffed, and shot in the head. The Zetas were showing a new approach for dealing with authorities. Police had once bullied criminals into paying up. Now the worm had turned.