Opinion | What I Am Listening for in Michael Cohen’s Testimony

For the final stage of the prosecutor’s case in the People of the State of New York v. Donald Trump, the prosecution is expected to call the witness who has received the lion’s share of attention since the indictment was brought a year ago: Michael Cohen.

Before the trial started, some observers thought Mr. Cohen would be an indispensable star witness. They said that without Mr. Cohen, the district attorney could not establish the elements of the charged criminal offenses. But having seen the proof laid out meticulously and methodically by the prosecution these past three weeks, I find myself wondering: Do prosecutors even need Michael Cohen as a witness? Does the jury need to hear from him?

To be sure, the case would not exist but for Mr. Cohen. It is he who first revealed to prosecutors in the special counsel Robert Mueller’s office (I was one of the special counsel prosecutors) and in New York the hush-money scheme to buy Stormy Daniels’s silence in the aftermath of the “Access Hollywood” tape’s disclosure.

But since then, Alvin Bragg, the Manhattan district attorney, has amassed evidence that appears to independently both prove the crime and corroborate Mr. Cohen’s account.

To call Mr. Cohen as a witness carries with it not only the reward of adding further critical evidence to the prosecution’s case, but also the risk of undermining the case with issues related to Mr. Cohen’s personal baggage. He is, like Ms. Daniels, a colorful character, catnip to the press, and his broken bond with his former boss, Mr. Trump, is inherently dramatic.

He joins a line of famous underlings who turned state’s evidence against their boss. The prosecution will be relying on the testimony of an insider testifying “up,” against his boss. And what those insiders also have in common is that they can speak to the inner workings of an alleged conspiracy.