Michael K. Williams, the actor who brought a hard-edge charisma to his portrayal of Omar Little, the sawed-off-shotgun-wielding stickup man on the pioneering HBO series “The Wire,” was found dead on Monday in his home in the Williamsburg neighborhood of Brooklyn, the police said. He was 54.

His longtime representative, Marianna Shafran, confirmed the death in a statement and said the family was grappling with “deep sorrow” at “this insurmountable loss.”

Mr. Williams was found at about 2 p.m., according to the New York City Police Department. The death is being investigated as a possible drug overdose, and the city’s medical examiner will determine the cause.

As Omar Little on “The Wire,” David Simon’s five-season epic on HBO that explored the gritty underworld of corruption, drugs and the police in Baltimore, Williams played perhaps the most memorable character on a series many consider among the best shows in television history.