Federal charges against Roger Stone Roger Jason StoneOur Constitution is under attack by Attorney General William Barr Justice IG investigating Stone sentencing: report Romney says Trump's protest tweets 'clearly intended to further inflame racial tensions' MORE do not have to point directly to collusion to be successful, a former federal prosecutor told Hill.TV on Wednesday.

"There has not been a charge of someone picking up a phone and saying, 'hey Russian actor, I need you to do this with the Trump campaign,' " Elliot Williams, a former Justice official in the Obama administration, told Hill.TV's Buck Sexton and Krystal Ball on "Rising."

"I don't think there has to be a charge of, this is where you colluded with precisely with the Russians for this to have been productive or successful," he said.

Special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE has accused Stone of lying to the House Intelligence Committee about his contacts regarding WikiLeaks, the organization that published hacked Democratic emails ahead of the 2016 election that U.S. officials later said were stolen by Russian military hackers.

Stone pleaded not guilty on Tuesday to the charges, which include obstruction of a congressional inquiry, witness tampering and five counts of making false statements to Congress.

"Paragraph 12 of the indictment, that's the big one ... where someone in the campaign directed another person to coordinate, or to talk to Roger Stone about the Russians," Williams said.

"Maybe that's charges of conspiracy to collude with Russia or defraud the United States. Maybe it's not, but you still have an intent on the part of the Trump campaign to get information on Hillary Clinton Hillary Diane Rodham ClintonJeff Flake: Republicans 'should hold the same position' on SCOTUS vacancy as 2016 Momentum growing among Republicans for Supreme Court vote before Election Day Warning signs flash for Lindsey Graham in South Carolina MORE that came from Russia," he continued. "I don't know if you can charge it criminally right now. Maybe you can, maybe you can't."

— Julia Manchester