Juan Raul Garza was born on November 18, 1956, in Brownsville, Texas. He was the son of Mexican migrant workers. When he was a child, his family moved to Michigan, where they spent several years. Garza grew up in a working-class family. His parents worked as migrant farmhands, and he often joined them in the fields to help with their labor. 

During his teenage years, Garza was known in his community for his work ethic. He became a family man, raising four children and marrying into a family connected to a respected pastor in the area. However, in the late 1980s, he moved back to Texas and became involved in drug trafficking.

Garza's drug trafficking operations encountered serious issues when some of his shipments were seized by police. This led him to suspect that some of his associates were informing on him. In April 1990, he ordered the murder of Gilberto Matos, a bodyguard for another smuggler, Erasmo De La Fuente. Garza believed De La Fuente had caused a major seizure of his marijuana. He instructed Manuel Flores and his cousin, Israel Flores, to wait for Matos at his auto shop. When Matos arrived alone, they forced him to lie on the floor and killed him.

Five months later, Garza wanted to kill De La Fuente directly. He took Israel and another cousin, Jesus Flores, to the nightclub where De La Fuente worked. Israel became too drunk to help and had to be taken home. Jesus returned with Manuel, and they waited until De La Fuente left the club. When he did, Manuel shot him twice. Jesus fired shots in the air to draw attention away from their escape. Afterward, Garza paid both men for their involvement.

In January 1991, Thomas Rumbo, who had been inspecting trucks for Garza, was killed personally by Garza. Rumbo had agreed to cooperate with the police after being caught loading marijuana, and Garza was not pleased. Garza, along with two workers, took Rumbo to a remote location, where he forced Rumbo to exit the truck and shot him in the back of the head before moving his body to hide it.

Despite these efforts to maintain his control, law enforcement gradually caught up with Garza. They tapped his phone, monitored his activities, and arrested associates who eventually cooperated with authorities. In February 1992, the U.S. Customs Service conducted a major operation against Garza's organization, leading to the indictment of his associates. Garza fled to Mexico but was arrested in November 1992 after trying to arrange a drug deal with an associate who had become an informant.

Garza was charged with multiple drug trafficking offenses and three counts of murder. In August 1993, he was convicted and sentenced to death. The jury found him responsible for the murders of Matos, De La Fuente, and Rumbo, as well as four other murders in Mexico. These included Oscar Cantu, who lost money in a deal; Fernando Escobar-Garcia, who lost a marijuana shipment; and Lauro Antonio Nieto, who mismanaged funds.

Garza also ordered the killing of Diana Flores Villarreal, after he believed she mocked him regarding his losses. Various associates testified against Garza in exchange for reduced sentences. After numerous appeals and discussions about racial bias in sentencing, Garza was executed by lethal injection on June 19, 2001. His last meal included steak and onion rings, and he expressed remorse for the pain he caused before his death.