. Arellano Felix, 58, was the head of the feared Tijuana cartel run by his brothers and operated on the Mexico-U.S. border near San Diego until his capture in Mexico in early 2002. He was extradited to the United States last April, and prosecutors said his guilty plea marked the demise of the violent cartel that dominated smuggling on the California-Mexico border in the 1980s and 1990s. "Arellano Felix led the most violent criminal organization in this part of the world for two decades. Today's guilty plea marks the end of his reign of murder, mayhem and corruption," U.S. Attorney Laura Duffy said. "His historic admission of guilt sends a clear message to the Mexican cartel leaders operating today: The United States will spare no effort to investigate, extradite and prosecute you for your criminal activities," she added. As part of a 17-page plea agreement, Arellano Felix admitted smuggling tons of cocaine and marijuana into California and conspiring to launder hundreds of millions of dollars. He also agreed to forfeit $100 million in profits under the plea deal, which is expected to land him 25 years in federal prison when he is sentenced on April 2. "It was a favorable deal to my client who faced a minimum of 40 years and a maximum of 140 years under the extradition agreement," defense attorney Anthony Colombo Jr. said. CARTEL A SHADOW OF FORMER SELF President Barack Obama's administration has worked closely with Mexican President Felipe Calderon in his army-led battle to crush warring drug gangs in a conflict that has claimed more than 46,000 lives since late 2006. At the height of his power in the 1990s, Arellano Felix smuggled hundreds of millions of dollars in narcotics through a 100-mile wide corridor stretching from Tijuana, south of San Diego, to Mexicali, south of Calexico. But after the death and capture of many of its leaders over the past decade, including three of Benjamin Arellano Felix's brothers, the Tijuana cartel, also known as the Arellano Felix Organization, is a shadow of its former self. Arellano Felix's brother Ramon, the cartel's flamboyant enforcer, died in a shoot-out in 2002. Francisco Javier is serving a life sentence in U.S. federal prison after being captured on a fishing boat in 2006, and Eduardo is in jail in Mexico awaiting extradition. With the downfall of the Arellano Felix brothers, the rival Sinaloa cartel run by Mexico's most-wanted man, Joaquin "Shorty" Guzman, has largely taken over the cartel's valuable turf in Tijuana. Appearing before U.S. District Judge Larry Burns at the hearing, Arellano Felix was neatly groomed and dressed in an orange jumpsuit. He said he took medication for migraine headaches, but when asked by the judge if it affected his decision to plead, he replied, "no." Among the former kingpins serving time in U.S. jails is former Gulf cartel leader Osiel Cardenas, who was extradited to the United States by Mexico in 2007 and is serving a 25-year sentence in Texas without chance of parole.