Good evening. I'm Ari Melba, anchoring our special coverage of this escalating Trump probe in New York.

And tonight, right now, you're watching a special live edition of the beat. We're following the pressure on Donald Trump, which actually exploded from the arrest talk this weekend through today's blockbuster testimony before the grand jury and some out-of-course statements

that broke within the last hour.

Moments ago, this Trump-aligned witness speaking out.

My only mission there today was to tell the truth about what Michael Cohn was saying at any point in time.

Michael Cohn decided, on his own, that's what he told us, on his own,

to see if he could take care of this. Is that what he told us? Was all of the remarks made factual?

Mr. Michael Cohen is here to respond at a moment. This is not just journalism. This is aspects of the

probe spilling out because Mr. Costello did speak to the

grand jury today. That's why he was so newsworthy. Mr. Cohen remains a key grand jury witness in a

case that Donald Trump now says will lead to Donald Trump's indictment. So what you're about to

see tonight in all seriousness, not because it's on MSNBC, not because it's the beep, but because,

quite frankly, of the people involved because of Mr. Cohen will be a part of this legal history,

a part of the path that Donald Trump himself claims will lead to his own indictment.

That is just moments away. But we always want to give you the context here, the reporting,

and the legal facts. And I want to chart for you before

I bring in our guests tonight, how this news, which is shaking so much of our understanding about

who may or may not become president or what comes next, hit like a bombshell over this weekend.

We have breaking news just now, former president Donald Trump Trump posting on Truth Social that he will be arrested Tuesday.

Protest, take our nation back. He's hoping to create fear that there'll be another January 6 type event or, you know, his followers will go shoot up another FBI office.

Local and federal law enforcement are on alert as Donald Trump is again calling

himself a victim. Anticipation is incredibly high. Will a grand jury decide to indict former president

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