ABC News' senior investigative reporter Aaron Katersky and investigator reporter Katherine Faulders discuss why the affidavit is crucial to the FBI’s investigation of former President Donald Trump. WATCH the ABC News Live Stream Here: https://www.youtube.com/watch?v=w_Ma8oQLmSM SUBSCRIBE to ABC NEWS: https://bit.ly/2vZb6yP Watch More on http://abcnews.go.com/ LIKE ABC News on FACEBOOK https://www.facebook.com/abcnews FOLLOW ABC News on TWITTER: https://twitter.com/abc #abcnews #abcnlupdate #investigation #trump