GEOFF BENNETT: A newly leaked audio recording appears to show former President Donald Trump discussing sensitive documents with people who didn't have security clearances during a 2021 meeting in Bedminster, New Jersey.

In this audio first obtained by CNN, the former president seems to acknowledge he knowingly held onto a document about a potential attack on Iran.

DONALD TRUMP, Former President of the United States: This totally wins my case, you know.

STAFFER: Mm-hmm.

DONALD TRUMP: Except it is, like, highly confidential.

STAFFER: Yes.

(LAUGHTER) DONALD TRUMP: Secret.

This is secret information.

STAFFER: Yes.

(LAUGHTER) DONALD TRUMP: I think we can probably -- right?

STAFFER: I don't know.

Well, we'll have to see.

Yes, we'll have to try to... DONALD TRUMP: Declassify it.

STAFFER: ... figure out a -- yes.

DONALD TRUMP: See, as president I could have declassified it.

STAFFER: Yes.

DONALD TRUMP: Now I can't.

But this is classified.

STAFFER: Yes.

(LAUGHTER) STAFFER: Now we have a problem.

DONALD TRUMP: Isn't that interesting?

GEOFF BENNETT: The two-minute audio recording could hold key evidence in Trump's indictment over his handling of classified information after he left the White House.

David Kelley is the former U.S. attorney for the Southern District of New York.

He is also an experienced trial lawyer and investigator.

And he joins us now.

Thank you for being with us.

DAVID KELLEY, Former U.S. Attorney, Southern District of New York: Happy to be here.

Thanks.

GEOFF BENNETT: On this recording, which the "NewsHour" hasn't independently verified.

Donald Trump is also heard saying -- quote -- "It's so cool" and that the information was classified and -- quote -- "highly confidential."

How might the special counsel leverage this recording as evidence in the indictment against the former president?

DAVID KELLEY: I think the special counsel would look at this recording as if he's opening a chest and suddenly the glow of gold shines in his face when he sees evidence like this.

It's a -- really quite a recording.

I think it does principally two things.

One, it helps prove one of the overt acts alleged in the indictment, namely, that he showed documents to folks who didn't have clearances.

And, two, it also really speaks to his state of mind.

Number -- it says that he knew that he couldn't declassify it.

He knew that he shouldn't be showing it.

So these are all things that kind of fly in the face of a lot of the public statements that he's making, including the one that he made today, that he did nothing wrong.

GEOFF BENNETT: Well, the episode is referenced in the special counsel indictment.

Donald Trump has, of course, pleaded not guilty to the charges against him.

How might a jury react to hearing this audio, as opposed to just reading the transcript in black and white?

DAVID KELLEY: Well, it's interesting.

You always like to have something more real-life than just a transcript, and having it here and hearing his own voice, because it's really unlikely that he will testify on his own behalf.

And I think the government will try to use his recordings to hear his own voice.

And, also, not only does it bring more life to the courtroom, but it's also a little less cumbersome than having just a transcript there and having people read along with it.

Having the real-life voice there is exponentially better, in terms of the form of evidence.

GEOFF BENNETT: As you mentioned, Donald Trump reacted to this leaked recording today.

Here's what he told FOX News while speaking in New Hampshire.

DONALD TRUMP: We did absolutely nothing wrong.

This is just another hoax.

It's called, I would say, election interference more than anything else.

But everything was fine.

We did nothing wrong.

And everybody knows it.

GEOFF BENNETT: How do his public statements, in which he oftentimes admits to the thing that he's accused of -- he often says: I took those documents.

I had every right to take those documents.

How does that complicate his legal case?

DAVID KELLEY: Well, look, there's two ways of looking at it, right?

One is just say that he's making a lot of statements that his defense lawyer typically would not like him to make, because it kind of flies in the face of the defense that they would like to construct, because the other thing, the other pieces of evidence, like this new recording, indicate that he did know what he was doing was wrong.

The other thing, from a -- another way to look at it, maybe from his twisted prism, is to think of it in terms of that he's kind of crazy, like a fox or dumb like a fox, insofar as he really thought that what he was doing was not wrong.

The problem with that is that, under all the circumstances, under all the evidence that I think they're going to present at trial, that that belief, if it was in fact, his belief, is simply not a reasonable belief.

GEOFF BENNETT: We also learned that investigators from special counsel Jack Smith's office are set to interview the Georgia secretary of state, Brad Raffensperger, about the special counsel probe into efforts to overturn the election.

Of course, Donald Trump back in January of 2021 called Raffensperger and pressed him to find the votes that he needed to turn that state in his favor.

Help us understand the value that a Brad Raffensperger has in the special counsel case.

DAVID KELLEY: A couple of -- a couple of different ways.

First off, he's not somebody who can be painted by the defense as kind of having an axe to grind, a political axe to grind, in particular, but more important that, whenever you have somebody who is on a recording to be there live in the courtroom, to help explain the context of the conversation, to get the background of how you came to have that conversation, and what you may have done in relation to that conversation is all important evidence that helps to bolster the strength of a pretty damning piece of evidence.

Or so it would appear from what we have seen so far.

GEOFF BENNETT: David Kelley, thanks for your time and for your insights.

We appreciate it.

DAVID KELLEY: Thank you.