Gabriel Sarmiento
Sarmiento, a native of Argentina, is best known for training former World Middleweight Champion Sergio Martinez. He has also trained former IBF junior featherweight champion Kiko Martinez and his brother, Pablo Daniel Sarmiento.
In 2003, Sarmiento was arrested and charged with aggravated battery in Spain. He was convicted and sentenced to eight years in prison. He later claimed he took the blame for one of his brothers, Orlando, who was an undocumented immigrant. Sarmiento was released in two years due to a mistake of forms. Upon his release, he moved to the United States and changed his name to Juan Diaz Leon.
Martinez won the World Middleweight Championship in 2010, and Sarmiento was named Trainer of the Year by the WBC. With the spotlight on Sarmiento, he revealed his real name. In March 2011, Sarmiento was arrested and extradited to Spain to serve the rest of his sentence. He was paroled in 2013.