Overview
- ATF records since 2012 show more than 40,370 .50‑caliber cartridges seized in U.S. border states, with roughly one‑third traced to the Lake City Army Ammunition Plant.
- Investigators recovered “L.C.”‑marked casings after the 2019 Villa Unión attack, and SEDENA reported early‑2024 use of incendiary armor‑piercing .50 rounds that penetrated an armored vehicle, killing a police officer.
- The investigation details a supply chain in which Lake City‑made or component .50 ammunition enters the U.S. retail market, with at least 16 online sellers identified before intermediaries traffic the rounds to Mexico.
- Lake City, a government‑owned, contractor‑operated plant, produces for the military plus a commercial line; the Pentagon defends commercial sales as saving taxpayers about $50 million a year.
- President Claudia Sheinbaum said her government is reviewing the findings and will open technical and diplomatic discussions with U.S. authorities on tracing and curbing the flow.