The New York Times reports:
President Trump had already been briefed on a whistle-blower’s complaint about his dealings with Ukraine when he unfroze military aid for the country in September, according to two people familiar with the matter. Lawyers from the White House counsel’s office told Mr. Trump in late August about the complaint, explaining that they were trying to determine whether they were legally required to give it to Congress, the people said.
The revelation could shed light on Mr. Trump’s thinking at two critical points under scrutiny by impeachment investigators: his decision in early September to release $391 million in security assistance to Ukraine and his denial to a key ambassador around the same time that there was a “quid pro quo” with Kyiv. Mr. Trump used the phrase before it had entered the public lexicon in the Ukraine affair.