Jacob Wohl, a conservative operative with a large internet following who has helped orchestrate efforts to smear opponents of President Trump, was charged this week with a felony in California related to the sale of a security, according to court documents.

Mr. Wohl, 21, a former blogger who has contributed to The Gateway Pundit, a right-wing news site, made headlines in recent months for his apparent involvement in efforts to promote false sexual assault allegations against Robert S. Mueller III, the former special counsel, and Pete Buttigieg, the Democratic presidential candidate.

Mr. Wohl, whose residence is listed as in Corona, appeared on Wednesday in Superior Court of California on a charge of selling an unregistered security in 2016, the complaint shows. A court spokeswoman said in an email on Thursday that he would be arraigned on Oct. 24.

David Wohl, Jacob Wohl’s father, who is listed in court records as his lawyer, said on Twitter on Wednesday that his son had been released on his own recognizance. “We expect a complete and total exoneration,” he wrote.