Four people have been arrested on federal charges stemming from the overdose death of actor Michael K. Williams last September, the U.S. Attorney’s Office in New York announced on Wednesday.

Irvin Cartagena, 39, is accused of selling heroin laced with fentanyl to Williams in Manhattan on Sept. 5, the day before Williams was found dead in his Brooklyn apartment. Three others — Hector Robles, 57, Luis Cruz, 56, and Carlos Macci, 70 — were also arrested on a charge of heroin and fentanyl conspiracy.

Williams rose to stardom with his performance as Omar Little on “The Wire,” and later appeared in “Boardwalk Empire,” “The Night Of” and “Lovecraft Country.” In interviews, he was candid about his struggles with addiction. He was 54.

According to the criminal complaint, investigators were able to trace Williams’ car using license-plate reader data, as well as location data from his phone, and discovered that he had traveled to a location in the 200 block of South 3rd Street in Manhattan the day before his death. Earlier in 2021, the New York Police Department had begun an undercover investigation of a drug-trafficking operation based in an apartment building on that block, according to the complaint.

Investigators obtained surveillance images of the sidewalk on that block, which show Williams greeting a group of people, including Cartagena, according to the complaint. The complaint includes an image in which a man identified as Cartagena appears to engage in a hand-to-hand transaction with Williams. The two later appeared to exchange phone numbers, and then Williams left and returned home, according to the complaint. He did not leave his apartment after that, and was found dead the following day in the same clothes as he was wearing in the surveillance images, according to the document.

Investigators were able to identify Cartagena using other surveillance images from a nearby store, matching a tattoo on his right arm to a prior arrest photo, according to the complaint.

The NYPD had used undercover informants to conduct controlled purchases of heroin glassines at that location prior to Williams’ death. According to the complaint, the glassines contained a logo for “AAA Insurance.” The same logo was found on glassines in Williams’ apartment, according to the complaint. The heroin obtained in the controlled purchases was also laced with fentanyl, the complaint states.

Investigators continued to oversee controlled purchases at the location in the weeks following Williams’ death, according to the complaint.

Cartagena, otherwise known as Green Eyes, was arrested in Puerto Rico on Tuesday, and is expected to appear in federal court there on Thursday, according to a statement from federal prosecutors. Robles, Luis and Macci were expected to appear in federal court in New York on Wednesday.

All four defendants face a charge of conspiracy to distribute fentanyl and heroin, which carries a mandatory minimum sentence of five years in prison. Cartagena is also accused of causing Williams’ death, which carries a 20-year mandatory minimum.

Update: David Simon, the creator of “The Wire,” tweeted in response that the charges are “awful.”

“I do not think Mike is honored or properly remembered by more incarceration in his name. Knowing him and his thoughts, I think he would be appalled at this. End the goddam drug war… When police charge in OD deaths, they assure more OD deaths. Fewer calls for ambos, fewer people waiting for ambos and trying to revive victims, more people rolled in rugs and dumped in alleys. Good local cops don’t charge this; headline-hunting feds do… It’s awful. Mike is neither honored nor remembered by this. He would, I think, be appalled.”