A federal judge sentenced twin brothers on Tuesday to 14 years each in prison for running a North American drug ring, according to The Associated Press.

Pedro and Margarito Flores received reduced sentences for turning on Mexican cartel leaders, including Joaquin "El Chapo" Guzman. The 33-year-old twins ran a drug ring worth nearly $2 billion.

Prosecutors say the brothers are among the most valuable informants in history. Chief U.S. District Judge Ruben Castillo said they were the biggest drug dealers ever to appear in the U.S. District Court in Chicago.

"Even though I am not going to sentence you to life, you are leaving here with a life sentence," the judge said to the twins.

"Each time you start your car (when you are out of prison), you are going to be wondering, is it going to start, or will it explode."

The twins made their brief statements before being sentenced.

"I'm ashamed, I'm embarrassed, I'm regretful," Margarito Flores said. "There is no excuse."

Pedro said, "I wanted to thank the United States (and federal agents) ... for allowing the opportunity not to spend my life in prison."

Back in 2012, the brothers pleaded guilty to a count of drug conspiracy charges behind closed doors at a hearing.

Tuesday marked their first public appearance since they started to cooperate with officials six years ago. Pedro and Margarito had private hearings for security reasons.

The brothers could have faced life sentences if their cooperation did not lead to indictments of nearly 50 drug cartel leaders.

Their father, Magarito Flores Sr., was kidnapped in Mexico as word spread of his sons' cooperation.

The twins ran their $2 billion North American operation from a Mexican ranch while issuing orders by phone.

They had networks that ran from Chicago to New York, Detroit, D.C., Los Angeles and Vancouver, British Colombia.