the "Zetas"

"A renegade band of Mexican military deserters, offering $50,000 bounties for the assassination of U.S. law-enforcement officers, has expanded its base of operations into the United States to protect loads of cocaine and marijuana being brought into America by Mexican smugglers, authorities said. The deserters, known as the "Zetas," trained in the United States as an elite force of anti-drug commandos, but have since signed on as mercenaries for Mexican narcotics traffickers and have recruited an army of followers, many of whom are believed to be operating in Texas, Arizona, California and Florida. Working mainly for the Gulf Cartel, one of Mexico's most dangerous drug-trafficking organizations, as many as 200 Zeta members are thought to be involved, including former Mexican federal, state and local police. They are suspected in more than 90 deaths of rival gang members and others, including police officers, in the past two years in a violent drug war to control U.S. smuggling routes. The organization's hub, law-enforcement authorities said, is Nuevo Laredo, a border city of 300,000 across from Laredo, Texas. It is the most active port-of-entry along the U.S.-Mexico border, with more than 6,000 trucks crossing daily into Texas, carrying about 40 percent of Mexico's total exports."