United States and Mexican authorities were on the heels of Arturo Beltran Leyva, alias ‘El Jefe de Jefes’ (The Boss of Bosses), for nearly ten months before they finally surrounded and killed him and several of his bodyguards in a massive four-hour shootout in one of Beltran Leyva’s safe houses in Cuernavaca on 16 December 2009.

The hunt unveiled a plethora of information about how deeply the drug kingpin had penetrated the Mexican security forces, as well as additional clues about where the cartels have been getting their guns.

*The project is an ongoing joint investigation by FRONTLINE, the Investigative Reporting Workshop, The Center for Public Integrity, InSight Crime, and the Romanian Centre for Investigative Journalism. Read the other chapters of the investigation here.

At the time of his arrest, Alfredo was carrying a Colt .38 Super that had been purchased from X Caliber Guns in Phoenix, Arizona, just three months earlier, according to government authorities. To be sure, one U.S. law enforcement source believes that weapons trafficked from this one U.S. gun store accounted for nearly half of the Beltran Leyva Organization’s supplies at any one time.Beltran Leyva’s demise can be traced back to a violent break between Mexico’s largest drug trafficking organizations, including that of Beltran Leyva, who ran the so-called Beltran Leyva Organization [BLO], and his longtime partner, Joaquin Guzman Loera, alias ‘El Chapo‘ (Shorty), who heads up the Sinaloa Cartel. The two men split in early 2008, after Beltran Leyva’s younger brother, Alfredo, was arrested as he and his entourage drove through Culiacan, Sinaloa.

The Beltran Leyvas blamed Guzman for their brother’s arrest and the war was on. The fighting eventually spread to several more Mexican states, and, as operatives from both sides took cover, they became vulnerable, communicating and shifting from place to place more often.

Arrests soon followed, including that of ‘Maria Fernanda,’ the name authorities gave to a Beltran Leyva operative and protected witness who, according to a report in El Universal newspaper, told authorities where safehouses were located and the modus operandi of the criminal syndicates. Her information led to the arrests of nearly 50 Beltran Leyva operatives, including numerous police and hitmen on the Beltran Leyva payroll.

By December 2009, not even Beltran Leyva’s closest confidants wanted his company, and for good reason. On 11 December, authorities raided a Christmas party in Cuernavaca, but Beltran Leyva and his brother, Hector, escaped. The Mexican authorities recovered 16 Romanian-made, AK-47-style assault rifles, known as WASR-10s, at the scene. Ten of the guns were originally bought at X Caliber.

In the days following, the United States intelligence agencies discovered Arturo was hiding at an upscale apartment building in Cuernavaca. The U.S. notified the Mexican government, and on Dec. 16, in an operation that included secretly evacuating all the residents in the multi-story residential building, Mexican Marines, with the army backing them up, moved in, leaving Arturo and four of his bodyguards dead.

Information gleaned from the scene led authorities to a Cuernavaca weapons safe house two days later where they seized 41 assault rifles, 4 handguns, 6,722 rounds of ammunition, 233 magazines, 7 silencers, 2 telescopes, one bullet-proof pickup, a laptop, 18 radios, a GPS and some illegal drugs.

Eighteen of the assault rifles were later traced back to X Caliber.

*Dudley is the co-director of InSight Crime. Young is a producer for FRONTLINE/Investigative Reporting Workshop.

Steven Dudley is the co-founder and co-director of InSight Crime and a senior research fellow at American University’s Center for Latin American and Latino Studies in Washington, DC. In 2020, Dudley...