Article IV refers to the law under the Mexican Federal Penal Code that permits Mexican Federal authorities to prosecute Mexican nationals who commit crimes in foreign countries or to prosecute other nationals who commit crimes against Mexican citizens outside of Mexico. To use Article IV, U.S. law enforcement officials must prove that either the suspect or victim is a Mexican national. Without this proof, Mexico lacks jurisdiction to prosecute. When Mexico has Article IV jurisdiction, the case must meet three conditions and requirements before Mexican Federal prosecutors can initiate and begin an Article IV prosecution. First, U.S. law enforcement agencies that are requesting Article IV prosecution must provide the fugitive's address in Mexico. Generally, the majority of the fugitives who flee from U.S. prosecution return to their hometowns. Second, U.S. prosecutors must confirm that the fugitive has not been "definitively judged" in the U.S. jurisdiction for the criminal act that the fugitive committed. U.S. prosecutors must submit a letter with the completed Article IV package stating that the fugitive has not been "tried and convicted" with no appellate recourse or "tried and acquitted." Finally, the offense or offenses for which U.S. law enforcement officials seek prosecution in Mexico must exist as a crime in both countries. This article also discusses the creation of liaison for the purpose of implementing Article IV, the preparation of the Article IV package, and filing the Article IV complaint. 3 notes