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WATCH: Vindman refuses to give information that could identify Trump whistleblower

Lt. Col. Alexander Vindman is declining to tell lawmakers who in the intelligence community he may have spoken to after he listened in to a July call between President Donald Trump and Ukrainian President Volodymyr Zelenskiy.

Vindman testified publicly on Nov. 19 before a House committee in the impeachment inquiry into President Donald Trump. Watch in the player above.

In response to questions from California Rep. Devin Nunes, the top Republican on the House Intelligence Committee, Vindman testified he would not answer on the advice of his lawyer and the recommendation by the committee’s chairman, Democratic Rep. Adam Schiff.

Schiff said Nunes’ questioning was an attempt to out a whistleblower who first revealed the essence of the call and whose formal complaint triggered the impeachment probe. The whistleblower based the complaint on conversations with people who were familiar with the call.

Schiff said “these proceedings will not be used to out the whistleblower.”

MORE: A guide to the impeachment hearings

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