that took place the day after giuliani provided a package to the state department containing unproven allegations against u.s. democratic candidate joe biden and his son hunter. a lawyer representing an indicted associate of president trump's attorney rudy giuliani announced that devin nunes met with ex-ukrainian officials last year. nunes denied multiple requests for comment from cnn. a series of tweets on friday from former national security adviser john bolton attracted a lot of attention mostly because of what they said and because bolton has been silent since leave the post. here's cnn's brian todd with more about it. >> reporter: he's been one of the ghosts of the impeachment hearings, on a list of key figures like mike pompeo, rudy giuliani and mick mulvaney who didn't testify.