Who is Roger Stone?
He's one of President Donald Trump's fiercest supporters.
Stone is a self-described 'dirty trickster.'
He's been in Republican inner circles for fifty years.
Stone was instrumental in the early month's of Trump's campaign.
He left the campaign (or was fired) in August 2015.
Stone communicated with a Russian hacker.
He also allegedly communicated with WikiLeaks founder Julian Assange.
Stone is now in crosshairs of the FBI.