Trump prosecutors' case is 'dead' and cannot be revived, says former Michael Cohen adviser

Former Michael Cohen legal adviser Robert Costello told "The Brian Kilmeade Show" that the prosecution in New York v. Trump has "nothing" that could revive their case against the former president. Speculation swirled this week that Trump's defense team could call Costello to the witness stand to lay out Cohen's credibility issues.

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ROBERT COSTELLO: There's nothing that I know about this case that could give the prosecution more life. This case is dead. It was dead on arrival. It never should have been brought. It should have been dismissed by this judge. He still has an opportunity to do that, but I doubt very much he will do that. So I don't think there's any downside with me [testifying]. I think there's only an upside, but it's a judgment call, you know? And I haven't been sitting in court, and I'd never seen any of these 12 jurors. So I have no feeling for what those people are like or which way they're leaning, or whether they made facial gestures during the weeks of trial that indicate which way to lean. So I'm not the right person to ask. The right person is the Trump team. They'll make whatever the correct decision is.

FORMER MICHAEL COHEN ADVISER: 'HE TOLD ME HE HAD NOTHING ON TRUMP,' STORMY NDA WAS 'HIS IDEA'

Costello told "America's Newsroom" on Thursday that he believes he should be called to testify, that the Trump trial grand jury did not get all the information they needed and that some jurors might have "Trump derangement syndrome."

Costello, who represented Cohen at the start of the federal investigation, has been released from his attorney-client confidentiality agreement so he is able to discuss the case. 

He joined Bill Hemmer and Dana Perino Thursday to explain that Manhattan District Attorney Alvin Bragg's team didn't want to see or hear exculpatory information that he provided and intended for the grand jury to hear.

Donald Trump's former lawyer  Michael Cohen returned to the witness stand on Tuesday in the NY v. Trump trial. (Getty Images)

Costello also detailed his April 2018 meeting where Cohen admitted that he was suicidal, as he saw enormous legal problems headed his way.  

"They were so bad in his mind that he was willing to kill himself and so I kept on going back and suggesting to him, listen, Michael, if you have something truthful on Donald Trump, now is the time to cooperate," Costello said. "He kept on saying over and over again, 10 to 20 times, 'I swear to God, Bob, I don't have anything on Donald Trump.'" 

Then, when discussing the Stormy Daniels NDA, Costello said Cohen specifically told him it was his idea to take care of the NDA because he had been contacted by a lawyer for Stormy Daniels, who said she was going to claim that Donald Trump had sex with her. 

"Cohen said, 'I didn't believe the allegation, but nevertheless, it would be embarrassing to Melania,' that's Michael Cohen's words he said, and so ‘I decided to take care of this myself,’" Costello recalled.

Fox News' Kendall Tietz contributed to this report.

This article was written by Fox News staff.