SAN DIEGO (KGTV) — El Mencho’s Jalisco New Generation Cartel has been one of the most significant suppliers of fentanyl, methamphetamine, and cocaine into the United States, using San Diego as one of its key entry points. Despite El Mencho’s death on Sunday, experts say, the drug supply is unlikely to stop.

The Department of Justice states that the cartel is known to move drugs through mules, commercial vehicles, maritime routes, and underground tunnels — through both official points of entry and unpatrolled areas along the border.

The cartel’s roots in synthetic drug trafficking stretch back decades.

ABC 10News spoke with David Shirk, a political science professor at the University of San Diego, who has been working on security issues in Mexico for around 25 years and launched the Justice in Mexico program in 2001, which focuses on cross-border drug trafficking. Shirk also works with the Council on Foreign Relations, the Wilson Center in Washington, D.C., and other various government agencies over the years.

Shirk said El Mencho and the Jalisco New Generation Cartel played an instrumental role in the market shift toward synthetic drugs that began in the 1990s.

“They were charged in the early to late 90s and early 2000s with bringing in precursor chemicals to Mexico that could be used to manufacture synthetic drugs,” Shirk said. “And they brought those chemicals in primarily from Asia.”

The cartel is known to control the Port of Manzanillo, located just south of Puerto Vallarta where chemicals used to manufacture fentanyl, methamphetamine, and cocaine arrive from primarily China, before moving north into San Diego.

According to the Drug Enforcement Administration, the Jalisco New Generation Cartel is a key supplier of fentanyl in the United States.

The Drug Enforcement Administration states that cartels’ drugs have reached all 50 states and, according to Shirk, have even made their way into Vancouver, Canada.

Shirk said the cartel has also expanded into other revenue streams targeting Americans, from fuel theft to real estate money laundering.

“Especially in the last few weeks, there’s been a lot of attention to fraud targeting especially US citizens who were buying condos or timeshares down in Puerto Vallarta and other parts of Mexico’s beautiful west coast,” Shirk said.

Now, with no clear successor identified, questions remain about what happens to the cartel’s leadership structure — and whether the flow of drugs into the United States will slow.

Shirk said history suggests it won’t.

“It’s really tough to try to stop the flow of drugs,” Shirk said. “About a little over 10 years ago, we took down one of the world’s most notorious drug traffickers, a guy named Chapo Guzman — Joaquin El Chapo Guzman. And the drugs kept coming. And they actually got cheaper over time. And so, there’s always gonna be another salesman.”