The US attorney said the crimes and charges resulted from a "public health crisis".
"And it has to stop. Deadly opioids like fentanyl and heroin don't care about who you are or what you've accomplished. They just feed addiction and lead to tragedy," the prosecutor said.
Sewell said police detectives in Brooklyn "lived this case, never relenting in their investigation until they could bring a measure of justice to Michael K Williams and his family".
According to court papers, Williams' death resulted from drugs sold by a drug trafficking organisation that has operated since at least August 2020 in Brooklyn's Williamsburg neighbourhood.
Authorities said members of the organisation sold the actor heroin laced with fentanyl on September 5.
The court papers contained photographs, including one in which defendant Irvin Cartagena can be seen executing the hand-to-hand transaction, authorities said. They added that the screenshots were taken from surveillance video.
It was not immediately clear who would represent Cartagena, 39, of Brooklyn, in court.
Authorities said that the men continued to sell fentanyl-laced heroin in broad daylight amid apartment buildings in Brooklyn and Manhattan even after knowing that Williams had died from one of their products.