CHICAGO (WLS) — The world could soon learn more about a plea deal between U.S. prosecutors and a dangerous cartel leader’s family.

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Ovidio Guzmán López is the son of Joaquin “El Chapo” Guzman, the jailed leader of the Sinaloa Cartel. Investigators claim he is accountable for 80% of the illegal drugs found on the Chicago streets.

Guzmán López was scheduled to appear in a federal court in Chicago on Wednesday to plead guilty to over a dozen charges, but this hearing has been postponed to Friday.

The central question surrounding the anticipated plea deal, according to former investigators, prosecutors, and cartel experts, is whether the man known as “El Raton” or “The Mouse” betrayed his old associates to receive a lesser sentence.

When Mexican police wrestled Guzman López into custody in 2023, and he was extradited to Chicago to face federal charges, his capture carved a deep notch in the notorious Sinaloa Cartel, founded by Guzman’s now imprisoned father El Chapo.

Alongside his older brother Joaquin Guzman López , U.S. prosecutors allege “Los Chapitos” operated the fentanyl wing of the international drug and gun trafficking operation.

“Ovidio has had a real impact on the safety and security of Chicago citizens,” said former Special Agent in Charge of DEA-Chicago Jack Riley.

“He’s responsible for thousands of deaths,” Riley said. “We knew that about 80% of all the narcotics coming to Chicago in the Midwest — because [El] Chapo had made Chicago his hub — were supplied by Sinaloa.”

Riley, who was a key figure in the U.S. hunt for Ovidio’s father El Chapo, said the structure and operators of the Sinaloa Cartel’s international drug flow could now be exposed in a carefully coordinated plea agreement.

Ovidio Guzman López tipped his hand last week in a federal court filing in the Southern District of New York, signing off on his intention to plead guilty to federal charges he faces here in Chicago.

Former federal prosecutor and ABC 7 Chief Legal Analyst Gil Soffer said at this point, it’s impossible to know what the terms of the plea agreement are, but this is still a major win for the government.

“Given who [Ovidio] is, the position he occupied and the profile of this criminal organization, it means a lot,” Soffer said. “[The plea deal] could range everywhere and anywhere from many years in jail still, given how many years he could have served, to the witness protection program for him and members of his family.”

In fact, this past May, Mexican authorities confirmed 17 relatives of Ovidio and his father crossed the border into the U.S., assisted by federal agents.

And perhaps a sign of what Ovidio and his family may be offering federal investigators, the real tell came when Ovidio’s older brother Joaquin delivered another Sinaloa Cartel kingpin, Ismael Zambada, also known as “El Mayo” to waiting federal agents in El Paso, Texas, last summer.

Both men were immediately taken into custody and have pleaded “not guilty” to drug trafficking charges.

Riley said it’s possible El Mayo may also be working on some sort of agreement with prosecutors.

“I wouldn’t be shocked if in the next few months we see something coming from El Mayo’s camp very similar to this,” Riley said. “One thing you know about these people, they are mass murderers, and they understand when their time is up.”

The I-Team asked Ovidio Guzman-López ‘ attorney Jeffrey Lichtman about the plea agreement but have not heard back.

Previously, Lichtman said that his client was not making any deals with prosecutors.

Last month, the U.S. imposed sanctions on two of El Chapo’s other sons — Archivaldo Ivan Guzman Salazar and Jesus Alfredo Guzman Salazar – and announced a reward of up to $10 million each for information leading to the arrest or conviction of the men.

The Sinaloa Cartel was also designated as a “foreign terrorist organization” by the U.S. State Department in February, which noted it is “one of the largest producers and traffickers of fentanyl and other illicit drugs to the United States.”

Now, as El Raton — the youngest son of the El Chapo drug dynasty — prepares to plead guilty, investigators say this could be the time the Sinaloa Cartel crumbles.

“You don’t send a swan down a sewer to catch a rat, you send a bigger rat,” Riley said.