The FBI has launched an investigation into the illegal selling of visas by officials in the busiest U.S. foreign consulate. NPR has learned the investigation centers on high-ranking officers at the consulate in Juarez, Mexico. It follows the conviction of Arcelia Betansis in federal court in El Paso, Texas. Betansis — a consular official — helped nearly 500 people get visas between 1998 and 1999. In return, she received cash, loans and gifts. The visas-for-sale scheme was uncovered when federal officials broke up a major drug-smuggling operation. NPR's John Burnett reports.