"If you're buying cocaine or high-level weed anywhere in the United States, you are buying it from the Mexican drug cartels," Chester County District Attorney Tom Hogan said.
And that has been a long-running trend.
"This has been building up for the past decade," Kane said during a recent interview in Montgomery County, with Mexicans overshadowing Dominican and Colombian trafficking organizations.
Colombia still produces the bulk of cocaine and heroin that ends up here, but it comes by way of Mexican cartels that have a stranglehold on the U.S. drug market.
Mexican wholesale drug-trafficking organizations have grown since 2008, according to the U.S. Department of Justice's 2011 Eastern Pennsylvania drug and gang threat assessment.
"Mexican [organizations] are the dominant wholesale suppliers of cocaine and heroin to drug-distribution groups in Philadelphia and Reading and in surrounding areas, such as Norristown, Montgomery County, and southern Chester County," it said.
Montgomery County District Attorney Risa Vetri Ferman said Norristown was "a place where we are vigilant" about removing opportunities for the illegal drug trade - whether they are homegrown, as most are, or come from Mexico.
"I don't think it's an issue of [Mexican cartels] taking over," Ferman said. "Our approach in Montgomery County has always been to make this an uncomfortable place for drug traffickers, wherever they come from."
In late 2010, Montgomery County authorities arrested Mexican-born Charbel Pita Rosales and accused him of operating a drug gang out of the Marquis Apartment complex in King of Prussia.
Prosecutors alleged Rosales and at least six other men were distributing more than 22 pounds of cocaine a month locally. Using telephone wiretaps, investigators found suggested connections to La Familia Michoacana, a violent Mexican cartel.
Rosales is scheduled to be sentenced next month, according to court documents; he was convicted last year of numerous felonies related to the drug operation.
Daniel Sweeney, a Bucks County deputy district attorney, said there was no evidence there of any great Mexican drug cartel presence. But police have intercepted marijuana, heroin, and cocaine that passed through Arizona, one of the transportation layovers for the cartels.
Many drugs have been intercepted on Route 1 and I-95, going both ways between New York and Philadelphia, he said.
Hogan said southern Chester County was part of the East Coast pipeline along I-95.
The great majority of the county's Latinos work hard and obey the law, he said. "But then salted in there by the [drug-trafficking organizations] are people who are transshipping drugs up and down the East Coast."
Hogan, who began dealing with Mexican cartels when he was an assistant U.S. attorney for the Eastern District of Pennsylvania, remembers warning Chester County in the early 2000s about them.
As a federal prosecutor, he worked a case in which a known Chester County dealer agreed to cooperate in catching his supplier.
The supplier, Hogan said, "was a Mexican national who had a residence in Georgia and regularly traveled up and down the East Coast, running back and forth between Chester County and Mexico, bringing large amounts of drugs back and forth."
Kane said the sophistication of the drug-distribution networks - and the violent crimes that can accompany them - required an intensive enforcement approach. At the state Senate budget hearing, she sought $3 million to establish a mobile street crimes unit that could work with overburdened local police departments in towns traffickers are targeting.
"It would have a comprehensive approach," Kane said, including using informants and officers on the streets and setting up wiretaps.
The "balloon theory" would guide the approach, as in when the air is squeezed out of one part of a balloon, another part expands. So if the mobile unit squeezed drug traffickers out of Lancaster, for example, its members would follow the traffickers to wherever they set up shop next.
From what the U.S. Drug Enforcement Administration sees in the distribution networks, "more of command and control is affiliated with Mexican cartels because it is distributed directly out of Mexico," said John M. Hamrick, a spokesman in the DEA's Philadelphia office.
"How far out do you want to make the link? It all comes from Mexico," Hamrick said.
"In the court of law, it's one big conspiracy."
Contact Carolyn Davis at 610-313-8109, firstname.lastname@example.org, or follow @carolyntweets on Twitter.