But an equally important part of his mandate is lesser known: his duty to write a report on his findings.

In this respect, Mueller, as a special counsel designated by the Justice Department, differs from other federal prosecutors.

Attorneys operate by a rule of put up or shut up—that is, they either bring criminal prosecutions or say nothing at all.

Some prosecutors will offer a brief explanation of their decisions not to prosecute, particularly in high-profile cases.

Rod Rosenstein, the Deputy Attorney General who was handling the Russia matter for the Attorney General, Jeff Sessions (who had recused himself), named Mueller under a specific federal regulation dealing with special counsels.

At the conclusion of the Special Counsel’s work, he or she shall provide the Attorney General with a confidential report explaining the prosecution or declination decisions reached by the Special Counsel.

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