A former U.S. narcotics official says the narco-terrorist leader killed by Mexican authorities on Sunday oversaw a cartel responsible for the deaths of hundreds of thousands of Americans.

Nemesio Rubén Oseguera Cervantes, known as “El Mencho,” was killed on Sunday inside his home by Mexican authorities as they tried to capture him, which was aided by U.S. intelligence. El Mencho was the leader of the Jalisco New Generation cartel (CJNG).

The cartel violently responded to his death, setting vehicles on fire and placing roadblocks throughout Guadalajara, which is the capital of Jalisco state. Guadalajara was nearly shut down on Sunday as violence gripped the city, with the city’s international airport only operating at a limited capacity.

The U.S. State Department was offering up to $15 million for information leading to the arrest and/or conviction of El Mencho, stating he was “one of the most wanted fugitives in Mexico.”

According to the State Department, CJNG has “the highest cocaine, heroin, and methamphetamine trafficking capacity in Mexico.” El Mencho has been indicted several times and was charged in the U.S. with conspiracy and distribution of a controlled substance (methamphetamine, cocaine, and fentanyl) for purposes of unlawful importation into the United States and use of a firearm during and in relation to drug trafficking crimes.

Robert Charles, former assistant secretary of state at the U.S. State Department’s Bureau of International Narcotics and Law Enforcement Affairs and Maine gubernatorial candidate, told Fox News Digital it’s not a stretch to say that the CJNG is responsible for the deaths of hundreds of thousands of Americans due to drug overdoses.

“This particular cartel is very violent, and they reach to every one of the 50 states in the United States,” Charles said. “So what we have to understand is, you know, we don’t like the verbiage of war when we talk about managing drug violence. But at end of day, it is drug violence, and one of the things it reinforces to us is we must support law enforcement.”

CARTELS OUTGUN POLICE: ROCKET LAUNCHERS SEIZED IN EL MENCHO RAID SPOTLIGHT CJNG FIREPOWER

Charles said it’s likely America will see “ripple effects” of El Mencho’s death.

While there isn’t an estimate of how many drugs are trafficked into America by the CJNG on an annual basis, individual seizures by the government paint a picture of how much product they’re moving into the U.S.

In September 2025, the U.S. Drug Enforcement Administration seized 92.4 kilograms of fentanyl powder, 1,157,672 counterfeit pills, 6,062 kilograms of methamphetamine, 22,842 kilograms of cocaine and 33 kilograms of heroin from the CJNG.

The cartel’s history of violence against Americans does not only stem from its broad drug trafficking network.

According to the New York Post, Isabel Ashanti Gomez, 22, was riding with her dad in his Ford F-150 in June 2025 when he tried to crash through a barrier believed to have been set up by the CJNG.

ALLEGED SINALOA CARTEL FENTANYL PRODUCER CHARGED IN NEWLY UNSEALED US FEDERAL INDICTMENT

Believing a rival gang member was driving the pickup truck, cartel members opened fire and killed Gomez.

Hours before she was killed, Gomez posted a birthday message to her uncle on social media.

CLICK HERE TO DOWNLOAD THE FOX NEWS APP

“I hope you keep celebrating many more birthdays. See you later, after I’ve had a shower,” Gomez wrote.

After El Mencho was killed on Sunday, the U.S. Embassy in Mexico told U.S. citizens in Jalisco state to shelter in place due to “ongoing security operations and related road blockages and criminal activity.”

Fox News’ Anders Hagstrom contributed to this report.

Related Article