Road to Mueller report paved by Watergate, Iran-Contra, Lewinsky, Waco

Special Counsel Robert Mueller, examining potential conspiracy between President Donald Trump’s 2016 campaign and Russia, is leading the latest in a series of high-profile U.S. investigations conducted by prosecutors outside usual Justice Department channels in recent decades.

The release of the findings by previous investigators analogous to Mueller has been handled differently, sometimes with voluminous reports and other times with no reports or with key elements kept under wraps for months and even years.

Mueller is preparing to submit a report to U.S. Attorney General William Barr on his findings, including Russia’s role in the election and whether Trump unlawfully sought to obstruct the probe. The Republican president has denied collusion and obstruction. Russia has denied election interference.

Barr already is coming under pressure from lawmakers to make the entire document public quickly, though he has wide latitude in what to release.

Here is an explanation of some past investigations and how their findings were made public.