Fentanyl-laced heroin has been blamed for more than 200 overdose-related deaths across the eastern half of the country in recent months.
But while much of the fentanyl seized in the investigation was packaged for individual use, none of the seized heroin was found to be mixed with fentanyl, authorities said. The legally produced painkiller is 80 times stronger than morphine.
Assistant U.S. Attorney Gary Shapiro alleged that the gang marketed its drugs to take advantage of the deadly heroin's notoriety, selling products with names such as "Max Pain," "Lethal Injection," "Fear Factor," "Drop Dead" and "Final Call."
He said none of the defendants had been charged with any of the fentanyl deaths.
In a series of raids Wednesday, agents seized more than 220 pounds of heroin, five firearms, four vehicles and an undetermined amount of cash, according to the Drug Enforcement Administration. More than 400 federal and local law enforcement officers were involved.
The criminal complaint Wednesday charges 47 members and associates of the Mickey Cobras gang. By early afternoon, 30 people had been arrested, including a female Chicago police officer.
Police spokeswoman Monique Bond said many of the arrests took place at the Dearborn Homes public housing complex, a Mickey Cobras stronghold a few miles south of the Loop, but the alleged drug ring extended to nearby states