A second drug dealer who worked in the Brooklyn crew that sold “The Wire” actor Michael K. Williams a fatal dose of heroin pleaded guilty in Manhattan federal court Thursday. 

Luis Cruz, a 58-year-old who also goes by the name “Mostro,” copped to one count of narcotics conspiracy for selling heroin and heroin mixed with fentanyl with the Williamsburg-based drug crew. 

At the brief hearing, Cruz told Judge Ronnie Abrams he sold drugs to support his own habit and to pay his bills — adding that he closed his eyes to the fact some of the heroin the crew sold contained fentanyl. 

If the case had gone to trial, federal prosecutors would have presented evidence including surveillance footage, undercover purchases of heroin from the crew and lab tests, Assistant US Attorney David Robles said. 

Last week, fellow crew member Irvin Cartagena, 39, also pleaded guilty to narcotics conspiracy in federal court. 

Cartagena completed the hand-to-hand drugs sale with Williams on Sept. 5, 2021, in front of an apartment building on South 3rd Street near Havemeyer Street in Williamsburg. 

The actor, who starred as Omar Little on “The Wire,” was found dead of an overdose the day after he bought the drugs from the crew. 

Cruz faces a minimum sentence of five years in prison. He’s scheduled to be sentenced Aug. 4.