Congress also investigated and sought information from Stone. A jury later determined he lied repeatedly to members of Congress. He lied about the identity of his intermediary to WikiLeaks. He lied about the existence of written communications with his intermediary. He lied by denying he had communicated with the Trump campaign about the timing of WikiLeaks’ releases. He in fact updated senior campaign officials repeatedly about WikiLeaks. And he tampered with a witness, imploring him to stonewall Congress.

The jury ultimately convicted Stone of obstruction of a congressional investigation, five counts of making false statements to Congress and tampering with a witness. Because his sentence has been commuted, he will not go to prison. But his conviction stands.

Russian efforts to interfere in our political system, and the essential question of whether those efforts involved the Trump campaign, required investigation. In that investigation, it was critical for us (and, before us, the FBI) to obtain full and accurate information. Likewise, it was critical for Congress to obtain accurate information from its witnesses. When a subject lies to investigators, it strikes at the core of the government’s efforts to find the truth and hold wrongdoers accountable. It may ultimately impede those efforts.