Special Counsel Robert Mueller has hired Andrew Weissman, an attorney known for “flipping people” into cooperating witnesses.

Mr. Weissmann was Head of the Justice Dept.’s Criminal Fraud Division prior to joining Mr. Mueller’s team. He has a past history of investigating organized crime and prosecuting Enron executives.

In both investigations, the prosecution used cooperating witnesses to help make their case. Mr. Weissmann’s hire could be indicative that Mr. Mueller is looking to make cooperating witnesses out of some of the President’s associates.

President Donald Trump, Vice-President Mike Pence, the former national security adviser Mike Flynn, strategist Jared Kushner, Trump confidante Roger Stone, former Trump campaign manager Paul Manafort, Trump’s personal lawyer Michael Cohen, and former Trump campaign adviser Michael Caputohave all retained their own attorneys.

Kathryn Ruemmler, a former attorney for the Obama White House, worked with Mr. Weissman when both served on the Enron Task Force. “He’s not afraid to lose, and that is sometimes an unusual quality,” Ms. Ruemmler told Reuters.

Robert Ray, the independent counsel who succeeded Kenneth Starr, said that he believes Mr. Mueller’s team may be at the point where they are flipping people.

“It would seem to me the time is now to make some decisions about what you have and what leverage can be applied to get the things you don’t have,” he told Reuters.