Special counsel Robert Mueller’s report on Russian election interference might never be seen by the public, according to Politico.

“That’s just the way this works,” said John Q. Barrett, a former associate counsel who helped investigate arms sales to Iran under former President Ronald Reagan. “Mueller is a criminal investigator. He’s not government oversight, and he’s not a historian.”

“He won’t be a good witness,” said Paul Rosenzweig, a former senior counsel to independent counsel Kenneth Starr who is now a senior fellow at the R Street Institute. “His answers will be, ‘yes’, ‘no’ and ‘maybe.’”

Previous government investigations, like the probe into whether former President Bill Clinton lied during a deposition or the Reagan administration’s arms deals with Iran, were conducted according to a post-Watergate law that expired in 1999, which required that investigators submit their findings to Congress if impeachable offenses are discovered. Mueller must only notify his superior at the Justice Department, deputy attorney general Rod Rosenstein, of his budgetary needs and of any “significant events” in the case.

“It’s such a unique situation. He knows there are a lot of questions he needs to address for the sake of trying to satisfy a wide variety of interests and expectations,” said Paul McNulty, a former deputy attorney general during former President George W. Bush’s administration.

McNulty added that a public explanation, like the one former FBI Director James Comey gave for not prosecuting former secretary of state Hillary Clinton over her use of a private email server, is “not Bob Mueller’s approach. I’d be surprised if he did that in written form. I think he’s about, ‘Where are the facts before us?’”