The Berks County District Attorney's Office said the investigation, called "Operation Trapped," targeted the drug ring based in Reading, Pa.
Search warrants were served late last week after an approximately eight-month-long investigation.
Three homes in Reading and one in Laureldale were searched, as were eight vehicles.
"This investigation entailed a number of undercover buyers. A lot of surveillance was conducted," said Berks County D.A. John Adams.
Of those vehicles, at least five of them have what the D.A.'s office called 'sophisticated hidden compartments,' or 'traps.'
Adams says accessing the compartments wasn't as easy as pressing a button.
"There is a combination of various things that have to happen, like turning on the wipers, turning on a signal, which will enable you to open the secret compartments, which are many times controlled by hydraulics," Adams said.
Adams added that investigators are not yet done looking through all of the eight vehicles they confiscated.
"This is an ongoing investigation. There may be other compartments in those vehicles that we haven't identified yet. Our search of these vehicles will continue," he said.
Authorities seized 2.4 pounds of crack cocaine, more than six pounds of powdered cocaine, around 11 pounds of methamphetamine and about eight pounds of fentanyl.
The drugs have a street value of $1.2 million, the D.A.'s office said.
Several loaded guns and a 'large stock' of ammunition were also seized as evidence, as was $4,000 in cash.
The suspects were identified as 28-year-old Selwyn Alcala-Garcia and 33-year-old Marcial Cooper, both of Reading, and 47-year-old Rashawn Brinkley of Laureldale.
All three suspects are being held on $1 million bail.