Hal Turner, the Web talk show host indicted for encouraging the killing of three federal appellate judges, pleaded not guilty Tuesday in federal court in Chicago. His lawyer told the magistrate judge that his client was a former FBI informant who had helped authorities thwart an assassination attempt on President Barack Obama.

The lawyer, Michael Orozco, also suggested a possible First Amendment defense when he told the judge that his client was only expressing opinions, albeit “outlandish” ones, by posting messages on his Web site that said three judges on the 7th U.S. Circuit Court of Appeals “deserve to be killed” for their June 2 ruling allowing a Chicago handgun ban to stand. Turner was arrested last month and appeared in U.S. District Court for Northern Illinois on July 28 for an arraignment and detention hearing.