Guide To Trump Impeachment Inquiry: What You Need To Know : NPR

The Democrat-led House of Representatives is leading an impeachment inquiry into President Trump. While momentum toward impeachment had been building among Democrats for months, House Speaker Nancy Pelosi, D-Calif., announced a formal inquiry in September — after a whistleblower complaint about a White House phone call with Ukraine. ....
https://www.npr.org/2019/10/28/771287237/trump-impeachment-inquiry-a-guide-to-key-people-facts-and-documents