Twin Chicago brothers reviled by Mexican cartels but praised by prosecutors as among the most valuable traffickers-turned-informants in recent history are set to be sentenced in a federal courthouse in their hometown amid tight security.

Tuesday will be the first public appearance by Pedro and Margarito Flores since they agreed to spill secrets to U.S. agents about Mexican drug lord, Joaquin "El Chapo" Guzmán and a half-dozen of his lieutenants in a nearly $2 billion trafficking franchise that spanned much of North America.

The risk of reprisals to the brothers, now 33, and anyone associated with them is so great even their lawyer's name has been kept secret. It's not clear if the attorney will speak in court or if the twins might step up to ask for leniency.

That may be unnecessary. Prosecutors themselves are asking for a remarkably lenient prison term of around 10 years as reward for the twins' cooperation that led to indictments of Guzmán and more than 50 others. With credit for time served, they could be out within a few years.

An attorney for Vicente Zambada, a Sinaloa cartel leader extradited to Chicago to face charges has sharply criticized the Flores brothers. Alvin Michaelson said at a 2011 hearing that the twins had a reputation "as murderers, as thieves, liars."

More On This...

Prosecutors' presentencing memo does address whether the twins might have ever killed. It describes how Guzmán once invited them to kill a trafficker who briefly kidnapped Pedro. The kidnapper turned up dead, but prosecutors say there's no clear proof the twins were to blame.

Details of the twins' story have been kept under seal for years. But with some filings unsealed recently, a fuller narrative can be told of their journey from flamboyant teen dealers in Chicago to associates of Guzmán, who was captured last year by Mexican authorities.

American officials portray the twins as among the most valuable drug traffickers who ever became informants. Chicago criminal lawyer Joe Lopez, who represented several clients indicted on evidence from the twins, put it more starkly: "They're some of the most significant rats in U.S. history."

Drug-world figures weighed in on their importance, too, in their own way. After word spread in mid-2009 that the twins had turned informants, their father was kidnapped, according to government documents. A note left for the twins on the windshield of his abandoned car read, "Shut up or we are going to send you his head." He is presumed dead.

Prosecutors cited his apparent death and the fact that the twins — as well as their mother, wives and children — will live in fear the rest of their lives as one reason for leniency. They also want to use the lighter sentence as an enticement to urge other cartel associates to cooperate.

The speed with which the 5-foot-4 twins ascended the drug-world hierarchy had something to do with location. Chicago's Little Village neighborhood, where they grew up, is surrounded by major rail lines and highways. It's an aspiring trafficker's dream — a transportation hub within a city that's a transportation hub to the nation.

As dealers in their teens, they had a reputation for being flashy but savvy, said Lopez, who had some clients from the same neighborhood. The twins' fondness for bling was illustrated by a list of items agents said they would forfeit. It included more than $400,000 in jewelry.

Only after the brothers fled Chicago around 2004 for Mexico, apparently fearing arrest following their indictment in Milwaukee, did their trafficking careers soar.

It's not clear how they first made contact with the Sinaloa cartel, but by mid-2005 they were summoned by Guzmán himself, according to government filings. Flown to an airstrip, they were taken to a secret mountain compound to hammer out drug deals with the kingpin.

From 2004 on, prosecutors say, the brothers ran their entire U.S. operation from a Mexican ranch, issuing orders by phone. Their network stretched to from New York, Detroit and Washington, D.C., to Los Angeles and Vancouver, Canada.

Strict rules governed the drug shipments. Guzmán's people got the drugs across the U.S.-Mexico border — sometimes via tunnels — and were responsible until the packages were transferred to Flores associates in the U.S. If the drugs were lost somewhere between that point and Chicago, the brothers would be on the hook for the full cost.

Court documents say the twins approached U.S. authorities on their own in the summer of 2008, offering to cooperate. The papers do not explain why, though it happened during bloody conflicts between cartels, and the twins may have feared they would soon fall victim.

Still, they continued to do business with the cartel, now with the aim of gathering evidence.

According to court documents, they met Guzmán again in his mountain compound in October 2008, when he made an ominous request of Margarito Flores: Could he obtain rocket and grenade launchers? They would use them, he was told, to attack a U.S. or Mexican government office to send the message that cartel suspects were not to be extradited.

The pressure on the twins was building.

Then something triggered U.S. agents' concern. On Nov. 30, 2008, they gave the brothers two hours' notice to get out of Mexico. They flew to Chicago with little but the clothing they wore.

But the brothers' scheming did not stop immediately.

In Chicago, the two sought to squirrel away millions in ill-gotten gains, toying with the idea of burying some of the money, filings say. While in custody, they also managed to purchase a $100,000 Bentley as a gift for Pedro's wife. They had to give it up when agents learned what they had done.

Like us on Facebook
Follow us on Twitter & Instagram