



All eyes are on Robert S. Mueller III as he begins his role as special counsel, leading the Justice Department’s probe into the Trump campaign’s possible ties to Russia. But that’s far from the only investigation into Russian meddling in the 2016 election.

The criminal investigation led by the special counsel is charged with determining if anything illegal occurred. Meanwhile, each of the four major congressional fact-finding investigations is working to expose transgressions it finds unethical.

Despite their differing goals, all the investigations are moving simultaneously and using much of the same information.





The investigations are looking into different things

On the whole, the special counsel and intelligence committees have a broader scope than the other committees.





Some have more access to information than others

Access differs both because of how aggressively the leaders pursue the investigation — the special counsel is expected to be more thorough — and the jurisdiction of the committees. They all are also expected to get unclassified information by requesting or subpoenaing testimony and documents from Trump affiliates and others involved.





The investigations can interfere with one another

Each probe will share information to some extent. The leaders of the Senate Intelligence Committee released a statement saying they “will engage with Director Mueller and our expectation is that he will engage with the Committee as well.”

But the investigations can also stymie one another. Congress has the power to grant “qualified immunity” to people who testify, meaning their statements cannot be used against them in court. Since it is hard for prosecutors to show the evidence they are using is independent of those statements, it can make their case significantly harder to prove.

On the other hand, some people may refuse to testify before congressional committees because they are under criminal investigation by the special counsel. Former national security adviser Michael Flynn has already refused to turn over documents to the Senate Intelligence Committee, invoking his Fifth Amendment right against self-incrimination.





They can deliver different consequences

Because the congressional investigations are political and the special counsel’s is legal, they have different standards for what qualifies as wrongdoing, and different ways to punish wrongdoers.





Their conclusions will probably have different levels of credibility

Because Republicans control both houses of Congress, Democrats are less inclined to view their committees’ conclusions as credible than the special counsel’s. And depending on how the special counsel investigation plays out — Trump-appointed Justice Department officials still have some control over the investigation — it may lose some credibility as well.

And not all congressional investigations are on equal footing in this respect — some have made a real effort for the investigation to be bipartisan, while others have appeared too cozy with Trump administration leaders and have had to recuse themselves.





Even with all these investigations — plus other related inquiries in the Treasury Department and other congressional committees — it could be years before they come to a close. And if charges are not filed, we may never know what happened, or did not happen, between the Trump campaign and the Russian government.

Sources: Information from staff reports and Eric Schickler, political science professor at the University of California at Berkeley. Additional special counsel details from Congressional Research Service [PDF] and the Justice Department.