The Sinaloa Cartel, one of Mexico's most powerful drug cartels, had effectively infiltrated the ranks of various Mexican government agencies and Mexico's Interpol. Its last known leader, Héctor Beltrán Leyva, was arrested in October 2014, having had a multimillion-dollar bounty placed on him by the governments of both the United States and Mexico. On August 11, 2011 the capture of one of the cartel's former top lieutenants, called "the last Beltran-Leyva link of any importance", prompted Mexican authorities to declare the cartel disbanded and extinct.
Born in the Sinaloan countryside in the 1960s, the Beltrán Leyva brothers — Arturo, Carlos, Alfredo, Mario Alberto and Héctor — worked closely with Joaquín "El Chapo" Guzmán, the leader of the Sinaloa Cartel, during decades of smuggling. Sensing a void in the rival Gulf Cartel after Osiel Cárdenas' arrest on March 14, 2003, the Sinaloa Cartel began to move into Gulf Cartel territory. The gangs fought each other in northern Mexican cities, resulting in the deaths of hundreds of people, including some civilians, police and journalists.
In 2004 and 2005, Arturo Beltrán Leyva led powerful groups of assassins to fight for trade routes in northeastern Mexico for the Sinaloa Cartel. Through the use of corruption or intimidation, the Beltrán Leyva Cartel was able to infiltrate Mexico's political, judicial and police institutions to feed classified information about anti-drug operations, and even infiltrated the Interpol office in Mexico.
During 2010, former Beltran Leyva cartel lieutenant Óscar Osvaldo García Montoya (a.k.a. El Compayito) attempted to regroup some cartel remnants under a gang he called La Mano Con Ojos. García Montoya was arrested on August 11, 2011; the Attorney General of Mexico had placed a $5 million pesos ($400,000 USD) bounty for his capture. Mexican authorities stated that García Montoya was "the last Beltrán-Leyva link of any importance", and that the cartel has been disbanded.
Allied forces of Los Zetas and Beltrán-Leyva remnants clashed on April 28, 2012 with gunmen of the Sinaloa Cartel in the Choix mountains. At least 32 armed men were confirmed dead. The renewed fighting in Sinaloa state between the BLO and Sinaloa Cartel is supposedly sparked by the incursion of the Sinaloa Cartel and its allies in Nuevo Laredo, traditionally the biggest Zeta stronghold.