Firearms Trafficking: U.S. Efforts to Disrupt Gun Smuggling into Mexico Would Benefit from Additional Data and Analysis, Report to Congressional Requesters [open pdf - 4MB]
From the Highlights: "The U.S. 'Southwest Border Counternarcotics Strategy: 2020' identified the trafficking of firearms from the U.S. into Mexico as a threat to the safety and security of both countries. The Mexican government has estimated that 200,000 firearms are smuggled from the United States each year. GAO [Government Accountability Office] was asked to report on U.S. efforts to counter firearms trafficking to Mexico. This report examines (1) the extent of U.S. agencies' knowledge about firearms trafficking to Mexico and (2) U.S. agencies' efforts to disrupt this trafficking and the extent to which they have assessed those efforts. GAO reviewed firearms tracing data, related analysis, and program information for fiscal years 2014 through 2020. GAO also interviewed U.S. and Mexican officials. This is a public version of a sensitive report that GAO issued in December 2020."
Government Accountability Office: http://www.gao.gov/