Flowchart: How the Mueller investigation could play out for Trump

Mr. Mueller could take pages from the playbook of Leon Jaworski, the Watergate prosecutor. If Mr. Mueller finds evidence of wrongdoing by Mr. Trump, he could try to use the grand-jury process to make the information public or disclose it to Congress. Mr. Mueller could name Mr. Trump as an unindicted co-conspirator in charges that are filed against others.

Like Mr. Jaworski, Mr. Mueller could also ask the grand jury to send a report about Mr. Trump’s actions, and supporting evidence, to the House Judiciary Committee. But Mr. Mueller would have to get Mr. Rosenstein’s permission for either or both steps.