Michael Cohen: A challenging star witness in Donald Trump's hush money trial

He once said he would take a bullet for Donald Trump. Now Michael Cohen is prosecutors' biggest piece of legal ammunition in the former president's hush money trial.

He once said he would take a bullet for Donald Trump. Now Michael Cohen is prosecutors' biggest piece of legal ammunition in the former president's hush money trial.

But if Trump's fixer-turned-foe is poised to offer jurors this week an insider's view of the dealings at the heart of prosecutors' case, he also is as challenging a star witness as they come.

There is his tortured history with Trump, for whom he served as personal attorney and problem-zapper until his practices came under federal investigation. That led to felony convictions and prison for Cohen but no charges against Trump, by then in the White House.

Cohen, who is expected to take the stand Monday, can address the jury as someone who has reckoned frankly with his own misdeeds and paid for them with his liberty. But jurors likely also will learn that the now-disbarred lawyer has not only pleaded guilty to lying to Congress and a bank, but recently asserted, under oath, that he wasn't truthful even in admitting to some of those falsehoods.

And there is Cohen's new persona — and podcast, books, and social media posts — as a relentless and sometimes crude Trump critic.

As Trump's trial opened, prosecutors took pains to portray Cohen as just one piece of their evidence against Trump, telling jurors that corroboration would come via other witnesses, documents and the ex-president's own recorded words. But Trump and his lawyers have assailed Cohen as an admitted liar and criminal who now makes a living off tearing down his former boss.

“What the defense is going to want the jury to focus on is the fact that he’s a liar" with a blemished past and a tetchy streak, said Richard Serafini, a Florida criminal defense lawyer and former federal and Manhattan prosecutor.