At a press conference, District Attorney Jen Schorn named Matthew James Byrne, 43, of Broomall; Joseph Byrne, 47, of Levittown; Khalik Kemp, 34, of Philadelphia; and Christian Garwood, 55 of Flourtown, as members of the "Byrne Drug Trafficking Organization."
According to police, the group -- allegedly led by Matthew Byrne -- shipped more than $5 million worth of narcotics from coast to coast.
Investigators say they used objects like speakers to conceal the drugs as they were shipped through the postal service.
"The drug trafficking organization would ship roughly in each shipment approximately 25 to 30 pounds of methamphetamine and cocaine by hiding them inside of large karaoke style Bluetooth speakers," Schorn said Wednesday.
Investigators said Matthew Byrne traveled to Southern California at least twice a month since January, where he would spend two to three days buying cocaine and methamphetamine from drug brokers with connections in Mexico.
He would then allegedly ship the drugs to his brother's home on Gable Hill Road in Bristol, Bucks County, and another home in Flourtown, Montgomery County.
"Those shipments would be received by their counterparts in Bucks and Montgomery counties and would later be prepared for distribution to individuals in our community," Schorn said.
During the course of the investigation, three shipments were intercepted at a United States Postal Service facility in Louisville, Kentucky.
Authorities said nearly $1.2 million worth of drugs were found stashed away in speakers.
In total, investigators said they tracked 12 shipments to locations in Bristol Township and Montgomery County allegedly containing hundreds of thousands of dollars worth of drugs meant to be distributed on the streets.
"We can connect the dots," Schorn said. "These drugs were getting into the hands of users shortly after being prepped for distribution in Bucks County and Montgomery County."
On Monday, all four of the accused who reside in Pennsylvania were hit with several charges, including corrupt organizations and possession with intent to distribute a controlled substance.
Two other men in California -- Ralph Brooks, 42, of Los Angeles, and Chaz Harness-Walker, 40, of Inglewood -- were also charged.
However, they have not yet been arrested.
Authorities said the investigation, which involved both state, local, and federal authorities across multiple jurisdictions, was still active as investigators worked to determine the full scope of the operation.
Assistant Special Agent in Charge for Homeland Security Investigations Philadelphia, Spiros Karabinas, said the results of the investigation were a reminder to bad actors that drug enforcement is indeed a priority.
"We will continue to work vigorously to prevent them from being trafficked, distributed and ultimately sold throughout our communities," said Karabinas.
All four Pennsylvania defendants were committed to Bucks County Correctional Facility on bail ranging from $1 million to $5 million.