This is an ABC News special.

Good morning and welcome to our special coverage of Special Counsel Robert Mueller's congressional testimony.

The Russian government's effort to interfere in our election is among the most serious.

Did you actually totally exonerate the president?

No.

Did your investigation find that the Russian government perceived it would benefit from

one of the candidates winning? Yes. Well, your investigation is not a witch hunt. It is not a witch hunt.

Would you agree that it was not a hoax that the Russians were engaged in trying to impact our

election? Absolutely. That was not a hoax. Did you know that? engaged in trying to impact our election.

Absolutely.

That was not a hoax.

Did McCann do what the president asked?

Well, I would have to refer you to the report on that.

The report is my testimony.

Welcome to the investigation. I'm Chris Vlasto, senior executive producer for ABC, and this is a very big day in the Mueller investigation.

Robert Mueller testified for more than five hours, two committees, the Judiciary Committee and the Intelligence Committee.

And obviously, over the last six, seven months, we've been covering this investigation in depth.

And so we're going to break down the testimony.

We actually have with us our two regulars, John Santucci and Matt Mosque, who have been covering the investigation since the very beginning.

And we have two special guests.

We have Terry Moran, senior national correspondent with ABC News,

and he's also our resident historian of American history here,

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