Guzman, whose nickname means "Shorty," has long been ranked among the richest men in the world by Forbes, and the DEA says he has surpassed late Colombian drug kingpin Pablo Escobar in power. The State Department has offered $5 million for his capture.
Though he was arrested in 1993, he has been on the loose since escaping from prison in a laundry truck in 2001. Now in his 50s, he built the Sinaloa cartel into what law enforcement officials consider the most powerful drug-trafficking organization in the world. Based in Culiacan, Sinaloa, the cartel has taken control of drug-trafficking in much of western Mexico, including the states of Baja California, Sonora and Durango, while the violent Zetas gang, which includes many gunmen with Mexican military training, dominates the east. The Sinaloa cartel deals in methamphetamine, marijuana, heroin and Colombian cocaine.
The Mexican government was thought to be zeroing in on Guzman ahead of July's presidential election. His capture would boost the fortunes of the ruling PAN party, which is trailing the PRI party in the polls.
The administration of current president Felipe Calderon had been accused of favoring the Sinaloa cartel while attacking lesser drug organizations. National Public Radio aired reports alleging that Mexican officials were helping the Sinaloa cartel to take control of areas run by other gangs, and that arrest data showed Sinaloa cartel members were arrested at a lower rate than members of other cartels. The Mexican government disputed the charge.