The mistrial came after the jury sent two notes -- one during its first day of deliberation on Friday and another on Monday -- saying it was hopelessly deadlocked over charges Hal Turner threatened to kill or assault a federal judge. A retrial was scheduled for March 1 in Brooklyn, where the case was moved based on a change-of-venue request.
Prosecutors had argued that Turner knew his Internet tirade, which insisted the judges "must die," could provoke violence by members of his radical audience. The defense likened Turner to a "shock jock" and argued he was expressing an opinion protected by the First Amendment.
The only juror to speak to reporters afterward, truck driver Richard Gardiner, said the jury voted 9 to 3 in favor of acquittal, with the majority seeing the government's case as weak. He said he held out for a conviction because he "did think it was a threat."
Turner, 47, of North Bergen, N.J., left the courthouse without commenting.
The case arose earlier this year after the 7th U.S. Circuit Court of Appeals -- Richard Posner, Frank Easterbrook and William Bauer -- upheld a ruling that dismissed lawsuits challenging handgun bans in Chicago and in suburban Oak Park, Ill.
Turner blasted the decision with a lengthy, inflammatory blog post. Authorities say he went too far by writing: "Let me be the first to say this plainly: These judges must die. Their blood will replenish the tree of liberty."
He later posted the judges' photographs, telephone numbers and work addresses, along with maps of a federal building that pointed out truck bomb barriers, authorities said. He also referenced the 2005 slaying of the mother and husband of another federal judge in Chicago, they said.
"Apparently, the 7th U.S. Circuit didn't get the hint after those killings," authorities say he wrote. "It appears another lesson is needed."
If convicted at the retrial, Turner faces up to 10 years in prison.
In a separate case, Turner is awaiting trial on state charges in Connecticut. He is accused of "inciting injury to persons" for urging blog readers to "take up arms" against state lawmakers there who proposed legislation to give Roman Catholic lay members more control over parish finances.