Louis Diaz  Louis "Lou" Diaz (born c. 1947) is an American former Drug Enforcement Administration (DEA) agent who was largely responsible for the arrest and conviction of Leroy Nicky Barnes a.k.a. "Mr. Untouchable". He was also instrumental in dismantling Barnes' entire drug trafficking organization known as the "Council". As an undercover agent, he also brought down members of the Medellin Cartel. Diaz is also an author and actor, who has participated in many major television series and Hollywood films under the pseudonym Lou Casal. Diaz was born in New York City and grew up in Red Hook, Brooklyn. He is the son of Spanish parents from the north of Spain. Diaz attended Most Holy Trinity High School in Brooklyn. After he graduated, he studied at St. Francis College, also in Brooklyn and at Queens College in Queens, New York, where he received his B.A. degree. In 1964, Diaz was a welterweight boxing finalist in the New York Daily News Golden Gloves. Diaz served in the United States Army. He was stationed in Germany where, as an amateur boxer, he won the 3rd Armored Division's middleweight championship. In 1971, Diaz was hired by the Bureau of Alcohol, Tobacco and Firearms (ATF) where he served as an undercover agent. While at ATF, Diaz made many high profile gun cases and arrested many organized crime members. In 1975, Diaz was hired by the Drug Enforcement Administration's (DEA) in New York City where he served 28 years as a special agent, 22 of which were spent working in an extensive undercover capacity. In 1975, Diaz's talents as an undercover agent caught the attention of his DEA superiors who assigned Diaz to the Nicky Barnes investigation. During the course of this investigation, Diaz infiltrated the Barnes organization at its highest levels, purchasing heroin and laundering money for Barnes' immediate subordinates and obtaining direct evidence against Barnes himself. Diaz spent one year around Barnes and his associates. Barnes was subsequently arrested and convicted on a myriad of drug charges including conspiracy. Barnes is serving a life sentence in prison. Diaz was also largely responsible for "taking down" all of the primary members of Barnes' drug trafficking organization known as the "Council". This case involved the direct intervention of President Carter who ordered the then U.S. Attorney General, Griffin Bell, to see that Barnes was tried and convicted to the full extent of the law. The Barnes case was the first federal trial in the United States in which an anonymous jury was impaneled because of Barnes' reputation to coerce or bribe the witnesses.