He was responsible for the kidnapping and murder of the U.S.
Drug Enforcement Administration (DEA) agent Enrique "Kiki" Camarena, Camarena's pilot Alfredo Zavala Avelar, the American writer John Clay Walker, and dentistry student Alberto Radelat in 1985.
After the murders, Caro Quintero fled to Costa Rica but was later arrested and extradited back to Mexico, where he was sentenced to 40-years in prison for murder.
Following his arrest, the Guadalajara Cartel disintegrated, and its leaders were incorporated into the Tijuana Cartel, Sinaloa Cartel, and JuĂĄrez Cartel.
Caro Quintero was freed from jail on August 9, 2013, after a state court concluded that he had been tried improperly.
However, amid pressure from the federal government of the United States to re-arrest him, a Mexican federal court issued an arrest warrant against Caro Quintero on August 14.
He remains at large, as a wanted fugitive in Mexico, the United States, and several other countries.
The United States is offering a $20 million bounty for his arrest.