Heriberto Lazcano's life was marked by betrayal: The Zetas drug lord was trained by the Mexican military to fight in its elite special forces,

Heriberto Lazcano's life was marked by betrayal: The Zetas drug lord was trained by the Mexican military to fight in its elite special forces, only to turn on them to create the country's most savage criminal group.
Mr. Lazcano, who Mexican officials said died in a firefight with the Navy on Monday, took his training to the heart of Mexico's crime machine, first working closely with the Gulf Cartel as an enforcer, then turning on his ex-employers under the banner of the Zetas.

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Heriberto Lazcano

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In the meantime, he built a church that bore a plaque in his honor, waged war along the U.S. border and played a cat-and-mouse game with the military that appears to have ended in his death Monday at either 37 or 41 years old, according to conflicting Mexican intelligence documents.
The Zetas name became synonymous with terror in Mexico. With its brutal tactics, the gang changed the world of drug trafficking in Mexico by expanding into crimes such as extortion and kidnapping.

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"He was a legend," said Alberto Islas, a Mexico City security expert. "In just 14 years, from when he left the special forces to today, he created a drug empire that has outposts world-wide—and one that's not disappearing with his death."
Unlike many of Mexico's kingpins, who grew up poor in the rugged Mexican sierra, Mr. Lazcano was the son of middle-class parents in the central city of Pachuca. A Mexican intelligence document seen by The Wall Street Journal said he entered the Mexican military at 17, eventually moving to the elite squad sent to uproot Mexico's drug mafia, which had been festering for decades.
In the late 1990s, Osiel Cardenas Guillén, then head of the powerful Gulf Cartel, made a deal with about 30 members of the elite squad, who traded their specialized training and connections to the military for jobs as bodyguards and hit men. They called themselves the Zetas. Mr. Lazcano, who reached the rank of corporal in the elite forces, became third in command. He was given the code name Z-3.
The soldier-turned-hit-man was responsible for instilling a military culture in the Zetas, designating new recruits with titles like "commander" and "lieutenant," and performing drills and army-style weapons training, Mr. Islas said.
"The introduction of the Zetas, with their specialized military background, increased the violence to never before seen levels," said Guadalupe Correa-Cabrera, a drug-trafficking expert at the University of Texas in Brownsville. "The Zetas brought with them a professionalization of the killing industry."
Mr. Lazcano became known for a punishment called "la paleta" or "the lollipop," in which victims would be stripped naked and beaten repeatedly with a board until nearly dead.
"He created a system of incentives and punishments," Mr. Islas said.
Ms. Correa-Cabrera said other drug-trafficking groups reacted by creating their own Zeta-like enforcer wings.
Mr. Lazcano's death, if confirmed, marks the end of an era for the Zetas. After more than a decade, Mr. Cárdenas Guillén was captured in 2003 and extradited to the U.S. in 2007.

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The aftermath of a casino fire blamed on the Zetas in Monterrey that killed 52.

In 2010, the Zetas broke with their onetime employers, the Gulf Cartel, and began a turf war that turned Tamaulipas into one of Mexico's most violent states. Homicides linked to drug trafficking leapt from 90 in 2009 to 1,209 in 2010.
Meanwhile, the Zetas have branched out from drug trafficking into extortion, kidnapping and smuggling of undocumented aliens to the U.S. They are considered responsible for some of the worst atrocities in Mexico in recent years, including a casino fire in Monterrey that killed 52 people in 2011.
Early in President Felipe Calderón's six-year term, he sent out thousands of troops and federal police to reclaim vast areas where the country's drug lords hold sway.
Since then, more than 60,000 people have died in drug-linked violence, most of them victims of internecine conflict between warring cartels.
Under Mr. Lazcano, the Zetas expanded their operations across many Mexicans states and throughout Central America, especially in Guatemala, according to a Mexican government profile of the organization. The gang has links to drug organizations in Colombia and Bolivia.
Corrections & Amplifications
Former Gulf Cartel head Osiel Cardenas Guillén was extradited to the U.S. in 2007. An earlier version of this story misstated the year as 2009.