The arrests turned a spotlight on what one expert said was an unusual pipeline directly linking a brutal international trafficking network to a pastoral suburb best-known perhaps for growing mushrooms.
"This will have echoes all the way back to Mexico," District Attorney Tom Hogan said, standing beside a board displaying the faces of those arrested by his office in recent weeks and of a dozen or so people yet to be picked up. "They will be talking about this in the drug cartels, saying, 'You know what, southern Chester County is not such a great place for us.' "
Atop the ring, he said, was Lemus, a 65-year-old East Marlborough Township resident known among ring members as El Viejo, "The Old One."
Arrested May 1 and jailed after failing to post $1 million cash bail, he faces more than 600 conspiracy, possession, and drug-delivery charges that could land him behind bars for life, officials said. Also charged were his son Francisco Lemus; nephew Mario Hernandez-Garcia; and his wife, Jovita Lemus.
A legal U.S. citizen, the elder Lemus has several homes in Mexico and allegedly traveled there regularly to build his connections. Though he was not a member of La Familia cartel, officials said, his son has direct ties to it - and their operation had access to its cocaine.
Their pipeline was fed from the Guanajuato region of Mexico and drug hubs including Houston, Phoenix, Charlotte, N.C., and Chicago, officials said.
Once here, those drugs hit the streets across the region, from Baltimore to Philadelphia to Cumberland County, N.J., officials said.
The yearlong investigation - dubbed Operation Telarana, Spanish for "spiderweb" - started with a few criminals agreeing to work as confidential informants in return for leniency, Hogan said.
It ended up with hundreds of secretly recorded phone calls and scores of suspects.
According to investigators, Lemus' distributors - some who sold directly to the streets and others who were intermediaries selling to other dealers - worked in blue-collar jobs. Some were landscapers; others worked on the farms that cover Kennett Square, the small borough where about half of the mushrooms in the U.S. are grown.
"It's much harder to spot them because they're bleeding into the landscape," Hogan said. "They're regular working folks. It's not until you drill into this that you get to see exactly how they're working."
It was easy to go unnoticed in a community that has long been a magnet for Mexican immigrants, many drawn first by work on the farms but who stayed to become legal residents and start families.
From 2000 to 2010, Kennett Square's Latino population doubled, from 1,470 to 2,963, accounting for nearly half of its residents. During the same time in Chester County, the fastest-growing in the state, the Latino population more than doubled.
Lemus also allegedly operated drug fronts to launder the proceeds, including a landscaping company in the Baltimore area. Local auto shops were also opened to store and distribute cocaine, Hogan said, without giving names.
He said the group likely moved about 2,000 kilos of cocaine over 20 years with a wholesale value of $60 million.
Nathan Jones, a post-doctoral fellow in drug policy at Rice University's Baker Institute, said the raid seems unusual because Mexican cartels typically distribute through connections with prison and street gangs.
He called it an example of "more direct market penetration into the wholesale and retail markets" in the United States by a Mexican trafficking network.
The Northeast is also one of the last remaining strongholds of the Colombian cocaine trade, which for decades has been chipped away at by Mexican traffickers, meaning this raid could prompt Mexican cartels to try to bolster their dominance in the area, he said.
Hogan said investigators broke the pipeline here with the help of federal agencies, including the DEA and members of the Philadelphia-Camden High Intensity Drug Trafficking Area Program.
But he said he didn't offer the case to federal prosecutors.
"We have the resources to take this case all the way, as far as it needs to go," Hogan said.
Officials making arrests this month scooped up caches of guns, drugs, jewelry, and money, and enough cars "to start a used-car dealership," Hogan said.
He said some of the dozen suspects not yet arrested appeared to have fled back to Mexico but he was confident they would be caught.
Lemus was picked up at his home, a modest two-story rented house on Oak Tree Road in East Marlborough Township.
On Wednesday, a neighbor, Dick Marquard, said a new family had recently moved in. The old renters, he said, kept to themselves and were rarely seen outside, though cars were always in the driveway.
"They didn't really make an attempt to interact," he said.