Lt Colonel Alexander Vindman is ‘the kind of witness that prosecutors dream about’: Mimi Rocah
Mimi Rocah was a federal prosecutor in the Southern District of New York and a distinguished fellow in criminal justice at Pace Law (screengrab)

Former Assistant U.S. Attorney Mimi Rocah said Lt. Colonel Alexander Vindman will be a "star witness" when he testifies before Congress.

Vindman, who is on active duty in the U.S. Army and received a Purple Heart for his service in Iraq, is scheduled to testify on Tuesday before the House Permanent Select Committee on Intelligence, the House Committee on Foreign Affairs, and the House Committee on Oversight and Reform.

He is the director for European affairs on the National Security Council and attended Ukraine President Zelensky’s inauguration with Energy Secretary Rick Perry, special envoy Kurt Volker and Ambassador to the European Union Gordon Sondland, who have become known as "The Three Amigos."

For analysis, MSNBC's Brian Williams interviewed Rocah on "The 11th Hour."

"Counselor, is this what you would call in the law a star witness?" Williams asked.

"Absolutely," Rocah replied.

"You know, this is the kind of witness that prosecutors dream about," she added.

"For a couple of reasons. One, as you pointed out, he’s a first-hand witness," Rocah explained. "He was on the call. So, amongst other things, he can be questioned about what were those ellipses in the summary, is there more? I don’t want to raise expectations because this call is damning as it is, but there are factual questions that he now gets to be asked."

"Two, the Republicans can’t make this argument -- which I think was a ridiculous argument, anyway -- but they can’t make it with him of, well, he doesn’t have any first-hand knowledge," she noted. "We need to know everything surrounding the call."

"And finally, he’s — I mean, leave it to Fox News -- but he’s active-duty military," Rocah noted. "We also have a person -- notwithstanding the allegations on Fox News tonight -- of impeccable character and that’s a pretty good witness to have."