Michael Cohen, who for nearly a decade was Donald Trump's trusted adviser, personal attorney, and self-described "attack dog with a law license," is scheduled to take the stand this morning as the prosecution's star witness in Trump's criminal hush money trial.

According to prosecutors, Cohen was in the room in when Trump and former National Enquirer publisher David Pecker agreed to a catch-and-kill scheme to hide negative information about Trump from 2016 voters, and Cohen himself made a $130,000 payment to Stormy Daniels to buy her silence about an alleged 2006 sexual encounter with Trump. The former president, who has denied the encounter took place, is on trial for allegedly falsifying business records related to his company's reimbursement to Cohen in 2017.

But Cohen's value to the prosecution's case could be endangered by the disbarred lawyer's credibility issues. Cohen pleaded guilty in 2018 to tax evasion, campaign finance allegations, and lying to Congress in what Cohen says was an effort to protect Trump. The former president's lawyers have also argued that Cohen perjured himself again when he testified at Trump's civil fraud trial last year, and accuse Cohen of making his livelihood off books and podcasts that antagonize Trump.

Cohen is the final key witness in the prosecution's case, after which the defense will present its case.