An accused leader of Mexico's Sinaloa drug cartel has been extradited to the United States to face charges in San Diego.

Victor Emilio Cazares Gastellum made an initial court appearance Monday on conspiracy and money laundering charges. Prosecutors said he was extradited Friday, nearly four years after his arrest by Mexican authorities at a highway checkpoint near Guadalajara.

The 52-year-old defendant, known as "El Licenciado," was indicted by a federal grand jury in 2007 in a sting called "Operation Imperial Emperor." The U.S. Drug Enforcement Administration investigation started in California's Imperial Valley, a farming region that borders Mexicali, Mexico.

Prosecutors say Cazares Gastellum's organization smuggled tons of cocaine to the United States.

Court records didn't list a defense attorney. Cazares Gastellum's next court appearance is April 4.