A .50 caliber gun used by Mexico's Jalisco cartel to takedown of a Mexican military helicopter in 2015 came from an arms supplier in Portland, Oregon, a joint Mexican-U.S. investigation has revealed. The Louisville Courier reported Wednesday that federal firearms officials had confirmed a link between the incident and Portland, Oregon. The investigation revealed that Eric Flores Elortegui, a 40-year-old Mexican native and US citizen, was responsible for supplying semi-automatic weapons to the Jalisco Cartel belt, also known as Cártel Jalisco Nueva Generación, or CJNG. The weapon was used to shoot down a Mexican military helicopter on May 1, 2015, during which several Mexican National Defense soldiers were on a secret mission to arrest Nemesio Oseguera Cervantes, or El Mencho, the top cartel boss in the world. The botched mission left nine Mexican police officers dead and many others injured when cartel members fired a gun at the helicopter's propeller, causing it to burst into flames and spin several times in the air before crashing to the ground. As a result of the incident, the Attorney General of Mexico asked the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) to trace the origin of the machine gun. “After he was located, we got information and were able to trace him back to Eric Flores,” Jason Chadi, a spokesman for the ATF's Seattle field unit, which also covers Oregon, told the Courier Journal. Elortegui is currently on the ATF's most wanted list. The ATF website lists Elortegui as being indicted in the U.S. District Court of Oregon in 2015 for making false statements in connection with the acquisition of firearms and smuggling goods from the United States.