SAN DIEGO — An alleged boss for Mexico's Sinaloa cartel has been charged by a San Diego federal grand jury on accusations of overseeing drug-trafficking operations at the Arizona border, according to an indictment unsealed Wednesday. Sergio Valenzuela Valenzuela, 52, who goes by the nicknames "Gigio" and "Yiyo," was indicted in 2018 and remains a fugitive. The indictment was unsealed on the same day Valenzuela was designated as a significant foreign narcotics trafficker under the Kingpin Act. The designation by the U.S. Department of the Treasury's Office of Foreign Assets Control means any pr...