In a June 2009 posting about their unanimous decision to uphold the gun ban, which the Supreme Court overturned in June, Mr. Turner wrote, “If they are allowed to get away with this by surviving, other judges will act the same way.”

Mr. Turner, who lives in North Bergen, N.J., also wrote a blog entry accompanied by photos of the judges in which he said they “deserve to be killed.”

Patrick J. Fitzgerald, the United States attorney for the Northern District of Illinois, where the appeals court is, issued a statement saying, “We are grateful that the jury saw these threats for what they were and rejected any notion that they were acceptable speech.”

Mr. Turner's lawyer, Peter Kirchhheimer, had no comment on the verdict. Federal prosecutors said the posting constituted a genuine threat.

Mr. Turner, who has said his audience includes members of the Ku Klux Klan and the Aryan Nation, and who once proclaimed that he would be “honored” to take credit for the murder of a federal judge's family, countered that the incendiary invective was protected speech. He testified that in saying the judges were worthy of death, he was expressing a critical opinion, not issuing a directive.

But the judges -- William J. Bauer, Frank H. Easterbrook and Richard A. Posner -- testified that they had felt imperiled by Mr. Turner's posting.

“My reaction,” said Judge Easterbrook, who is chief judge of the Court of Appeals for the Seventh Circuit and who wrote the handguns opinion, “was that somebody was threatening to kill me.”

It was an unusual trial with a witness roster full of opposites. There were the three judges, who are more accustomed to issuing orders than answering questions. And there was Mr. Turner, who was known for making flamboyant antigovernment and white supremacist statements, but who also was a paid informant for the Federal Bureau of Investigation and said he was assigned to gather information on precisely the sorts of people who might agree with and act on those statements.

Mr. Turner had said that his rhetoric was a tool to help the F.B.I. flush out violent extremists and that agents sometimes encouraged racist and provocative language.

The relationship with the F.B.I. was rocky. Mr. Turner quit, then returned. He was let go, then reinstated, then let go again. The bureau said it finally severed its relationship with Mr. Turner because of what it called “serious control problems.”

Mr. Turner was indicted in Chicago but the trials were moved to Brooklyn after his lawyer requested a change of venue.

The first trial ended in a hung jury last December. During that proceeding, prosecutors introduced a series of statements by Mr. Turner, including one in which he called government officials sleazy and cunning tyrants, but they did not present exhaustive information about any threats. In that trial, the jury was split 9 to 3 for acquittal.

The second mistrial, in which the judges testified, was declared in March. The division of that jury was not known; the trial judge instructed the jurors not to speak with reporters.

But the latest jury appeared to have little difficulty in reaching a consensus.

After the verdict, Mr. Turner was directed to remove a black belt and a yellow tie before being taken into custody. As marshals led him from the courtroom, he called out to his mother, Kathy Diamond, that he loved her. “There goes the First Amendment for everybody,” she said a moment later. “This was not justice.”

Mr. Turner faces a maximum penalty of 10 years in prison and a fine of $250,000.