After one day of deliberations, a federal jury on Thursday found a Bloods gang leader from the Gowanus Houses in Brooklyn guilty of all 21 counts he had been tried for, including three murders, racketeering and drug trafficking.
The trial of the man, Ronald Herron, in Federal District Court in Brooklyn, brought testimony from fellow gang members and former friends; a rap star named Uncle Murda; and a linguistics expert who testified about how rappers used lyrics.
Mr. Herron, 32, a rapper known as Ra Diggs, depicted life in the projects in rap videos that were shown during the trial. The defense said he had become a serious artist while in prison, ultimately putting in long hours in the recording studio and in clubs promoting his career.
Judge Nicholas G. Garaufis set a sentencing date of Oct. 1.
In and out of jail and prison since his first stint in the correctional system, Mr. Herron, prosecutors said, wielded an enormous amount of power. They said he had risen from a low-level drug dealer to the top of his Bloods “set,” called the Murderous Mad Dawgs, and controlled the turf around the Gowanus and Wyckoff Houses.
He had been acquitted in state court on one of the murders that the jury on Thursday said he had committed. Federal prosecutors said he intimidated witnesses so that the state case against him fell apart. They quoted him as saying he “beat a body” and said that was an admission that he had committed the murder and gotten away with it. One of those witnesses said in the federal trial that he was “fearful what would happen to me if I testified.”
The jury asked for copies of testimony from three witnesses, along with a rap video of Mr. Herron’s whose title included an expletive, and surveillance camera footage from city housing projects, before it reached its verdict.
He was convicted of murdering three men associated with drugs: Frederick Brooks, Richard Russo and Victor Zapata. The family of Mr. Zapata attended most of the trial, and listened to the verdicts with hugs and quiet tears.
Loretta E. Lynch, the United States attorney for the Eastern District of New York, said in a statement, “He styled himself a rap artist, but the jury’s verdict makes clear who Herron really is: a drug dealer and murderer who sought power through fear and intimidation.”