Christopher Coke, a Jamaican drug trafficker whose arrest last summer came after a monthlong manhunt that left scores dead in Kingston, pleaded guilty on Wednesday to racketeering conspiracy charges in Federal District Court in Manhattan.

The guilty plea emerged during an hour of quiet dialogue between Mr. Coke and a federal judge, a proceeding that stood in sharp contrast to the violence generated last year as the Jamaican authorities searched for Mr. Coke, a neighborhood don, at the request of American prosecutors.

Mr. Coke, a short, balding man of 42, pleaded guilty to trafficking large quantities of marijuana and cocaine, as well as approving the stabbing of a marijuana dealer in New York. He faces a maximum sentence of 23 years in prison; the plea deal does not require him to cooperate or to testify on behalf of the government in any proceeding.

“I’m pleading guilty because I am,” he told Judge Robert P. Patterson Jr.

In seeking Mr. Coke’s extradition, Preet Bharara, the United States attorney in Manhattan, charged that for more than a decade Mr. Coke had controlled an international drug ring from his stronghold of Tivoli Gardens in Kingston.