sentences:  In 1997, general Jesús Gutiérrez Rebollo, who had been appointed by president Ernesto Zedillo as head of the "Instituto Nacional de Combate a las Drogas", was arrested after it was discovered that he had been collaborating with the Juárez Cartel.In another infamous incident, Mario Villanueva, a member of the PRI and outgoing governor of Quintana Roo, was accused of drug trafficking charges in 1999.When the evidence against Villanueva became strong enough to warrant an arrest, he disappeared from the public eye two days before the end of his term, being absent at the ceremony at which he was to hand the office over to his elected successor, Joaquín Hendricks Díaz.