The whistle-blower, moreover, identified multiple White House officials as witnesses to potential presidential misconduct who could corroborate the complaint, the people said — adding that the inspector general for the intelligence community, Michael Atkinson, interviewed witnesses.
Mr. Atkinson eventually concluded that there was reason to believe that the president may have illegally solicited a foreign campaign contribution — and that his potential misconduct created a national security risk, according to a newly disclosed Justice Department memo….Mr. Atkinson also found reason to believe that the whistle-blower may not support the re-election of Mr. Trump and made clear that the complainant was not in a position to directly listen to the call or see the memo that reconstructed it before it was made public, according to the Justice Department memo, which referred only to a single phone call between Mr. Trump and an unnamed foreign leader.
Instead, the officer heard about the call secondhand from unidentified White House officials who expressed concern that Mr. Trump had “abused his authority or acted unlawfully in connection with foreign diplomacy,” the memo said. Still, Mr. Atkinson concluded after an investigation that the information in the complaint was credible.