A portion of that interview was used as justification to investigate Trump for firing Comey. The FBI claimed that Trump gave changing reasons for firing Comey, including that he had decided to fire Comey before Rosenstein made the recommendation. May 12, 2017: Trump tweeted a warning to Comey, saying Comey should “hope that there are no ‘tapes’ of our conversations.” “In addition, this investigation will also seek to determine whether President Trump and others yet to be named obstructed and/or conspiracy to obstruct any associated FBI investigation.” The memo also connected Trump’s firing of Comey to allegations that Trump’s 2016 campaign had colluded with Russia.