Among those charged in the indictments were three reputed leaders of Mexico's most violent trafficking organizations.

Today's announcement followed years of investigations by federal agencies including the Drug Enforcement Administration and Immigration and Customs Enforcement, in cooperation with Mexican and Colombian authorities.

The charges were filed in 12 separate indictments naming 43 individuals in U.S. federal court in Brooklyn and Chicago.

U.S. Atty. Gen. Eric Holder praised the "bilateral cooperation" between Mexico and the U.S. throughout the investigations.

Some of the suspects, including the reputed head of the Sinaloa cartel, Joaquín "El Chapo" Guzmán, have been indicted previously and remained at large. Holder said the new indictments are not a futile exercise and declared his intention to bring the defendants to justice in the U.S.

"These are not symbolic acts that we are taking today," Holder said at the Justice Department, appearing with two U.S. attorneys and ICE and DEA officials.

Holder also acknowledged that criminal conduct had not taken place solely in Mexico, noting the indictment of individuals who'd received shipments in Chicago.

"The audacity of these cartels' operations is met only by their sophistication and their reach," Holder said.

Three of the most powerful suspected leaders were charged in both Brooklyn and Chicago: Guzmán, Ismael "El Mayo" Zambada García and Arturo Beltran Leyva, who are alleged to be former and present leaders of the Federation, an alliance centered around the Sinaloa cartel.

Together, the four Brooklyn and eight Chicago indictments, which were unsealed Wednesday and today, charge that the three men were responsible for importing and distributing more than 200 metric tons of cocaine and additional quantities of heroin between 1990 and 2008.

More than 32,500 kilograms of cocaine have been seized, including about 3,000 kilograms seized during the Chicago investigation and about 7,500 kilograms from the New York investigation.

The DEA estimates that about 90% of the cocaine that enters the U.S. comes from Mexico.

Patrick J. Fitzgerald, U.S. attorney for the northern district of Illinois, said today's indictments were "among the most significant drug conspiracy charges ever returned in Chicago."

Fitzgerald noted that the defendants allegedly used "practically every means of transportation imaginable to move these large amounts of drugs and to funnel massive amounts of money back to Mexico."

The drugs were moved by car, truck, boat, ship, submarine and plane, including Boeing 747 cargo aircraft.

As part of their operation, the three alleged Sinaloa leaders are believed to have smuggled more than $5.8 billion in cash proceeds from the U.S. and Canada back to Mexico.

Today's indictments seek forfeiture of these proceeds.

"We've learned we must not only go after the leaders, but their money," Holder said. "If we suffocate their funding sources, we can cripple their operations."

Today's indictments also add to the growing list of drug traffickers apprehended or wanted by the U.S. government.

Earlier this year, federal authorities arrested more than 750 individuals in the United States and Mexico who they charged were affiliated with the Sinaloa cartel. And 15 defendants were charged in previous indictments - 10 in Chicago and five in New York -- including customers, carriers and distributors for the cartels.

In all, 58 individuals have been charged in the investigation coordinated between the U.S. attorneys' offices in Brooklyn and Chicago. All but one of the defendants face life sentences if convicted of the charges.

During today's announcement, ICE Assistant Secretary John Morton said ICE has invested more than 20,000 hours in these investigations.

ksherry@tribune.com