The non-governmental body first applied that label to Guzmán in 2013 to highlight how his Sinaloa cartel dominates Chicago's drugs trade. The city is also a key transit hub for Sinaloa's U.S.-wide distribution.
Internal documents of the Drug Enforcement Administration obtained by The Associated Press reveal that drug agents first got information on escape plans in March 2014. That was about a month after Guzmán was captured in Mazatlán, Mexico.
More than 30 employees who were in the prison during the escape are being interrogated to determine if they are involved, among them Valentín Cárdenas Lerma, director of the prison; the deputy director, guards and the medical staff that supplied drugs to Guzmán.
The escape undermined Mexico's assertion it can deal with top drug lords at home and doesn't need to extradite them to the U.S.
El Chapo provocó burlas en las redes sociales
He blamed it all on the 'corruption' in Mexico.
El entrenador del Tri Panamericano emitió una fuerte queja al gobierno mexicano
El comisionado Nacional de Seguridad, Monte Alejandro Rubido, confirmó que Joaquín "El Chapo" Guzmán se escapó del penal de máxima seguridad del Altiplano.
Mexico's most notorious drug slipped out of the prison through a tunnel more than 1.5 km (1 mile) long which led to a building site in the local town, National Security Commissioner Monte Alejandro Rubido told a news conference on Sunday.