WATCH: Schiff’s full questioning of Vindman and Williams | Trump impeachment hearings

Trump's first impeachment - 2020 Rep. Adam Schiff, the chair of the House Intelligence Committee, questioned Lt. Col. Alexander Vindman, an Army officer who works for the National Security Council, and Jennifer Williams, an aide to Vice President Mike Pence, on Nov. 19, in a public hearing as part of the impeachment inquiry into President Donald Trump. Schiff asked Vindman what was his "real-time reaction" was to the July call. "Without hesitation, I knew I had to report this to the White House counsel," Vindman said, saying he had concerns about what he had heard in the call. Repeating his opening statement, Vindman said the call was "improper" for the president to "request an investigation into a political opponent especially from a foreign power where it was at best dubious that this would be a completely impartial investigation." Vindman and Williams both listened in on a July phone call in which Trump asked the president of Ukraine to investigate former vice president and 2020 presidential candidate Joe Biden and his son, Hunter. For more on who’s who in the Trump impeachment inquiry, read: https://www.pbs.org/newshour/politics/whos-who-in-the-trump-impeachment-inquiry Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: Facebook: http://www.pbs.org/newshour Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Snapchat: @pbsnews Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe