A NOTE ON THE SOURCES

This book is based extensively on interviews with federal agents from the FBI, IRS, and DEA, as well as federal prosecutors. I also consulted thousands of pages of court transcripts, not just from the José Treviño trial, but also from dozens of others involving members of the Zeta cartel.

The name Alma Perez is a pseudonym, which the FBI agent requested that I use for the safety of her family. Accordingly, the names of her family members have also been changed. For privacy reasons the name Veronica Cárdenas is a pseudonym, as well as the name of Scott Lawson’s former girlfriend. All other names in the book are real.

Tyler Graham, who was the key source for the FBI in the investigation, declined to be interviewed for this book, as did José Treviño. To reconstruct the scenes and events surrounding them, I relied on court testimonies, accounts from agents and others who interacted with them, wiretap recordings, and other investigative documents. For anything in quotation marks, I relied on the agents who were present, court transcripts, wiretap recordings, investigative documents, and media reports, which are cited in the endnotes section. In addition, I interviewed various quarter horse racing experts and a law enforcement official in Mexico, all of whom requested anonymity because they feared retribution.