Special counsel Robert Mueller has impaneled a grand jury in Washington, DC, as part of his investigation into Russia’s interference in the 2016 election.

Almost immediately after the news broke, the tweets and “BREAKING NEWS” headlines started to fly. The assumption is that this is a big deal, a major step in the investigatory process. But most people aren’t lawyers (myself included), and therefore don’t totally understand what the formation of a grand jury actually means — or how much we should read into it.

I reached out to 20 of the top law professors in the country and asked them about the implications of this new grand jury. Does it suggest the case is broadening in scope? Should we assume that indictments or subpoenas are next?

Nine of the experts say this is a significant but not necessarily explosive development. It means the case is progressing and that perhaps Mueller believes he has compelling evidence of wrongdoing. Especially significant, according to Fordham law professor Jed Shugerman, is the fact that Mueller has requested a grand jury focused on Russia: “That commitment means that 1) Mueller expects this new grand jury to be doing a lot of special work, and 2) it will be reviewing classified material.”

Eleven of the experts say this is an inevitable step in the process and therefore doesn’t tell us all that much. “The real news,” says Ric Simmons, a law professor at Ohio State University, “would be if Mueller had not eventually impaneled a grand jury.”

Their full responses, lightly edited for clarity and style, are below.

A grand jury suggests the investigation is expanding

Jessica Levinson, law professor, Loyola Law School

First, it is important to remember what grand juries are and what they do. They are a group of citizens who are charged with deciding whether or not there is reasonable cause or probable cause to believe a person (or persons) has committed a crime. Essentially the grand jury serves a gatekeeping function to determine if there is enough evidence for an indictment. Under the Constitution, a grand jury must be impaneled in "capital" or "infamous crimes" in federal court.

Second, what does it mean that a grand jury is impaneled? When we say a jury has been impaneled, it is another was of saying that a jury has been chosen. Grand jury proceedings are led by a prosecutor, they operate in secret, and so there is only so much we can read into any news we hear about the grand jury.

The fact that a grand jury has been impaneled means that Robert Mueller's investigation is progressing, and perhaps widening, as there is already a grand jury looking at allegations related to [former National Security Adviser] Michael Flynn. It does not mean that anyone has been criminally indicted. It means they have chosen a group of citizens to continue to look into the investigation of election interference.

It also likely means that Mueller is in the point in the investigation in which he will begin to subpoena documents and obtain testimony from witnesses under oath.

Samuel Gross, law professor, University of Michigan

Federal grand juries do two things: indict people (or occasionally decline to indict them) and help prosecutors conduct investigations. In run-of-the-mill cases, their main role is to issue indictments based on investigations that have already been conducted. But in some big cases, they are critical to the investigations themselves because grand juries — unlike prosecutors and law enforcement agents — can issue subpoenas and compel witnesses to answer questions under oath.

Mueller's investigation is nothing if not a huge case. The fact that a grand jury has been impaneled simply means the investigation has reached the point where the investigators have — or soon will — subpoena witnesses to testify to what they know, under penalty of perjury. That testimony will be taken in secret. Depending what happens later, we may or may not learn who was called and what they said.

Jens David Ohlin, law professor, Cornell University

This suggests that Mueller's investigation isn't an investigate-and-file-a-report-with-Congress type of deal — it's an investigate-and-indict effort. Although it is hard to predict the future, the existence of the grand jury suggests to me that indictments are more likely than not.

Robert Weisberg, law professor, Stanford University

No one can know for sure. It could mean he has come close to amassing enough evidence that he will soon be able to ask for an indictment against someone. It could mean there are witnesses who did not want to speak to his people directly, so he needs the grand jury's subpoena power to get them to talk but he still isn't sure if he has probable cause. Also, sometimes the grand jury subpoena has a way of making a reluctant witness who is also a potential defendant into, shall we say, a very cooperative citizen.

The reports that Mueller is broadening the investigation to include financial crimes is important because it confirms the suspicion that Mueller is interested in complex schemes of legally questionable loans from Russians or money laundering thereof. These deals could involve Paul Manafort and possibly people in Trump's business enterprises and beyond. This might explain Trump’s motives for fearing Comey as much as he did.

“Sometimes the grand jury subpoena has a way of making a reluctant witness who is also a potential defendant into, shall we say, a very cooperative citizen.”

— Robert Weisberg, law professor, Stanford University

Renato Mariotti, former federal prosecutor, 2007-2016

The news that Robert Mueller impaneled a grand jury tells us that he believes there is sufficient evidence that a crime was committed to warrant a criminal investigation. That is hardly surprising, given that Mueller already hired 16 prosecutors and that the evidence available to the public was already sufficient to warrant an investigation, which is why Mueller was appointed.

That said, typically a grand jury is impaneled at the very beginning of an investigation, not at the end. That’s because grand jury subpoenas are an important tool that prosecutors can use to require people to produce documents or testify under oath before the grand jury. So you can expect Mueller and his team to issue many subpoenas in the months to come.

Although only a grand jury can issue an indictment, which is the only way that someone can be charged with committing a felony pursuant to the US Constitution, merely impaneling a grand jury does not mean that Mueller will seek an indictment.

Typically indictments are sought at the very end of an investigation, after all of the testimony and documents have been obtained. One exception is if a prosecutor hits a “wall” and believes that indicting an individual or individuals will lead to their cooperation and ultimately to additional evidence. At this point, however, it’s safe to say that decisions about whether and whom to charge are months away.

Jed Shugerman, law professor, Fordham University

Mueller going to a grand jury is not a big deal by itself. The big deal is that he is impaneling a special grand jury devoted to the Russia/Trump investigation. Normally, a federal grand jury of as many as 23 people sits for a year or 18 months hearing all kinds of crimes: murders, white-collar crimes, etc. Mueller was using one of those general grand juries in Virginia for the Flynn investigation.

But now Mueller has impaneled a special grand jury in DC focused on Russia, and that commitment means that 1) Mueller expects this new grand jury to be doing a lot of special work, and 2) it will be reviewing classified material. A special grand jury devoted to a single investigation is very rare. Perhaps a clearer signal of Mueller's case is his recent hire of Greg Andres, a former prosecutor specializing in foreign bribery and fraud. Andres would not leave his law firm if he did not expect to be very busy and very central to this case.

As for timing, compare Mueller to the Whitewater investigation of the Clintons. The first special counsel, Robert Fiske, took about five months to get to a grand jury. It took Mueller just a bit over two months. He may be moving faster than most people expected.

Victoria Nourse, law professor, Georgetown University

Impaneling a grand jury does not mean that any charges will follow. A grand jury is in charge of the charges, which is to say, they — not Mueller — determine whether the evidence provides "probable cause" (very good reasons) that a crime was committed. The grand jury issues the charges — the indictment.

Prosecutors seek a grand jury even if they do not know an indictment will issue. In fact, prosecutors sometimes do this in high-profile cases to avoid responsibility: It’s the jurors who decide.

Having said that, here’s why this event is quite significant:

1. The first bit of "news" is that any charges definitely go beyond Gen. Flynn. There was already a different grand jury, in a different place (Virginia), on that case. This DC grand jury is separate — that means the case has moved beyond Flynn, at the very least.

2. The second bit of "news" (known to lawyers but perhaps unknown elsewhere) is that grand juries can force the revelation of various documents and testimony of witnesses, under oath, which includes tax returns, witnesses who testify under oath, etc.

3. My personal speculation is that Mueller would not have done this if he did not have significant evidence. Mueller is a class act. I doubt he would risk his reputation, even among a few dozen people, without something that he already knows is potentially very serious.

Andy Wright, law professor, Savannah Law School

Impaneling a grand jury is a signal that the Mueller investigation is ramping up, especially given that it’s a new grand jury in addition to the one looking at Michael Flynn. Mueller started by building an impressive legal team to include several areas of expertise such as obstruction of justice, organized crime, financial crimes, and counterintelligence matters. There have been reports that he has sought to preserve evidence and follow leads.

A grand jury is the natural next step in a large investigation. It can assist the investigation by issuing subpoenas and receiving witness testimony. It largely operates in secret, so we won't hear much from Mueller's team. We will, however, likely hear from witnesses brought before the grand jury or parties the grand jury subpoenas from time to time. So while there is no guarantee Mueller will seek indictments, this is a significant milestone in the special counsel's Russia investigation.

David Harris, law professor, University of Pittsburgh

The initiation of the grand jury process is meaningful but not surprising. It tells us that the investigation is moving forward, in the way that any serious investigation would. We already knew it was a serious investigation, given the way Mueller staffed his office.

The grand jury is a standard and powerful investigative tool — it allows prosecutors to compel witnesses to testify, under oath; to produce documents and other evidence; and to do this under the watchful eye of a prosecutor. It does not mean that anyone will be indicted. But it can be used, very effectively, to uncover evidence, even from reluctant witnesses, and sometimes that evidence leads the case in new directions.

Grand jury formation is a natural step in the process, so it doesn’t really tell us all that much

Asha Rangappa, associate dean, Yale Law School

Investigations proceed methodically: Each lead that's followed will either resolve questions or raise new ones, or both. The impaneling of the grand jury means that the avenues followed by Mueller's team so far have raised enough new questions that obtaining more information — either from people or records — is necessary. Once that's obtained, it still needs to be parsed and analyzed, which can take a while. So if this were a season-long TV show, this might only be episode three or four.

Mueller would be expected to get financial records at this stage. The reason that "follow the money" is Investigation 101 is because money trails are harder to cover up, and can reveal relationships and networks that might not otherwise be apparent. Of course, a review of financial transactions and records can reveal new crimes as well (let's not forget that Al Capone was ultimately convicted for tax evasion).

Finally, the criminal avenues that Mueller is pursuing through the grand jury are likely happening on a parallel track to an active counterintelligence investigation. Since the primary goal on the counterintelligence side involves identifying and thwarting the activities of Russian intelligence officers in the US, it would use investigative techniques like FISA [Foreign Intelligence Surveillance Act] warrants that are separate from the grand jury and remain classified to the public — and which may in the end not result in any prosecutions at all.

“If this were a season-long TV show, this might only be episode three or four.”

— Asha Rangappa, associate dean, Yale Law School

Ric Simmons, law professor, Ohio State University

While I understand that the media is eager for any signs of progress from the Mueller investigation, I would attach very little significance to the impaneling of a grand jury in this context. Indeed, the real news would be if Mueller had not eventually impaneled a grand jury. For complicated cases such as this one, investigative grand juries are routinely used to assist prosecutors.

Grand juries can issue subpoenas for documents and can compel individuals to give testimony. (All of this is done in secret, which is another benefit of the grand jury from Mueller's perspective: He can conduct the investigation in private, which will be much easier than if the media were following his every move.)

Investigative grand juries do not necessarily ever indict anyone; they may (in theory) work for months and then determine there is no probable cause to believe a crime has been committed — or the prosecutor may simply have the grand jury disbanded and never bring charges. Or the grand jury could eventually choose to indict.

But as of now, all we know is that Mueller is doing his job and thoroughly investigating these allegations.

Julie O’Sullivan, law professor, Georgetown University

I’m surprised that this is news — my reaction is "of course" Bob Mueller has a grand jury convened. One investigates potential white-collar crimes through grand juries. Mueller will call before the grand jury everyone who has had any possible involvement in the alleged collusion and the alleged obstruction, and get them on the record under oath.

They cannot decline to testify unless they take the Fifth [that is, invoke the Fifth Amendment to the US Constitution, which says that no person "shall be compelled in any criminal case to be a witness against himself"], and only then if they have a valid argument that their testimony may incriminate them.

Any decent white-collar lawyer will urge clients to take the Fifth, but a lot of politicians and businesspeople think they cannot do so without unacceptable collateral employment or reputational consequences, and so they testify. If they are smart, they will not lie. (Martha Stewart and Scooter Libby should serve as cautionary examples.)

Unless reporters stake out the grand jury rooms and are able to figure out who is testifying, don’t plan on hearing anything more about this for a while. Grand jury proceedings are, by law, secret. It is only if an indictment issues and a trial ensues that we will find out what witnesses said — because Mueller is a thoroughgoing professional and there will be no leaks.

Joshua Dressler, law professor, Ohio State University

I think it is much too early to know what this ultimately means, except that the investigation has moved further along. It is to be expected that a grand jury would be impaneled at some point. The grand jury provides Mueller a mechanism to subpoena documents and require persons to testify (or take the Fifth Amendment route) if they were otherwise uncooperative.

Obviously a prosecution cannot proceed except by indictment, and that can only proceed through indictment by a grand jury; but it is much too early for us to know how close he is, if at all, to recommending that. Right now I only see this as an investigatory mechanism.

Steven Duke, law professor, Yale University

The fact that Robert Mueller is convening a grand jury does not mean he is on the verge of indicting anyone. He needs the grand jury for its subpoena power and his ability to question witnesses in secret without counsel. It was inevitable that he would employ the grand jury in his investigation.

David Alan Sklansky, law professor, Stanford University

It's not a surprise that he's impaneling a grand jury in DC. The surprise would be if he didn't. The use of grand juries is entirely routine in complex federal criminal investigations, and you impanel a grand jury in the district where the crimes you are investigating may have occurred.

The order appointing Mueller directed him to investigate "any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump" and "any matters that arose or may arise directly from the investigation." It's hard to imagine how Mueller could carry out the first part of this charge in any serious way without looking into the history of financial entanglements between Russia and people associated with the Trump campaign, including Trump and his family. And any financial crimes the investigators come across would fall squarely within the second part of his charge.

Stephen Schulhofer, law professor, New York University

This isn’t big news. True, it’s the next step in any investigation that’s going anywhere, but it was bound to happen, and sooner rather than later, given what we already know. It doesn’t imply that the cases are stronger (i.e., ready for indictment) or weaker (i.e., needing a new way to get more evidence) than we thought before. But I think the media is right to write about it, for the sake of readers who might be focused on the latest tweet du jour or might have forgotten that the issue is still alive.

As for the news that Mueller is looking into possible financial crimes, that has broad implications for the scope of individuals who could be implicated and for the range of evidence that becomes relevant, but it does not change the significance of the fact that a grand jury has been impaneled.

“It's not a surprise that he's impaneling a grand jury in DC. The surprise would be if he didn't.”

— David Alan Sklansky, law professor, Stanford University

Richard McAdams, law professor, University of Chicago

It is important in the sense that it is a necessary step to a federal indictment. But convening a grand jury doesn’t mean there will be an indictment of anyone, or even that it is likely. It means that Mueller has reached a point where he would prefer to investigate possible crimes by having a grand jury issue subpoenas, rather than having his personnel attempt to conduct voluntary interviews.

Paul Rothstein, law professor, Georgetown University

This development is no big deal. Prosecutors do it routinely when they are investigating. It is just a standard tool in an investigation and does not mean an indictment is imminent, nor does it necessarily mean anyone in particular is a target.

It is just a way to have the ability to subpoena witnesses to talk and give up documents. A subpoena means they must comply or plead the privilege against self-incrimination — that is, "take the Fifth," meaning the Fifth Amendment to the Constitution.

George Thomas, law professor, Rutgers University

Grand juries can issue subpoenas for documents and for witnesses to testify under oath. A grand jury is therefore a useful tool to investigate leads. A district judge must convene a grand jury "[w]hen the public interest so requires," per Federal Rule of Criminal Procedure 6(a)(1), but I imagine any judge would convene a grand jury whenever a special prosecutor requests one, without any showing of cause.

In this case, it must mean that Mueller thinks he might be able to uncover evidence of wrongdoing, but on its face, it tells us nothing about what he has uncovered so far.

George Fletcher, law professor, Columbia University

The basic function of the grand jury is to provide backup for the prosecution. If a grand jury agrees in a closed meeting — with laypeople but not defense counsel present — that there a sound basis for Mueller to proceed, it will be virtually impossible for Trump to fire him. The grand jury also keeps minutes of its proceedings.