The U.S. Congress is preparing to subpoena testimony from Ghislaine Maxwell, who is serving a 20-year sentence for sex trafficking.

Roger Stone, a former advisor to President Donald Trump, leaves the Federal Courthouse on Jan. 25, 2019, in Fort Lauderdale, Florida. (CNN) - Roger Stone says an attempt by prosecutors to show his jury a clip from the film "The Godfather: Part II" -- that could suggest he's a mob boss -- is out of bounds. "It makes Roger Stone the Michael Corleone character in this analogy -- an iconic violent godfather of the Mafia," Stone's lawyers wrote. Stone had referenced the scene and the mobster character as he allegedly threatened a witness in the Russia investigation about what the witness, Randy Credico, might say about Stone to Congress. He also argues that the jury shouldn't be guided to believe Credico and Stone have mafia ties.