Derek Chauvin's grand jury indictment is still pending. Here's how that process works

People walk past a mural showing the face of George Floyd, an unarmed handcuffed black man who died ...

As police killings and trials of officers accused of murder continue to grip the nation, people are becoming increasingly familiar with the ins and outs of the United States legal system. We frequently hear (and learn) about things like bail, qualified immunity, and the varying charges people can face. But there's one aspect of the legal system that continues to confuse: the grand jury.

You might remember hearing about grand juries in November 2014, after one decided not to indict police officer Darren Wilson for the killing of teenager Michael Brown in Ferguson, Missouri. Or in December 2015 when a grand jury similarly decided not to indict a Cleveland cop in the killing of 12-year-old Tamir Rice. Or perhaps you recall a more recent case, when a grand jury decided not to charge any of the officers who shot and killed 26-year-old Breonna Taylor in her Kentucky home last March. Really, I could keep going.

But if you aren't a legal expert, the actual details of these proceedings — and the lack of resulting charges — could be confusing. Why do grand juries have so much power, and what does it actually mean to indict someone? Why would a grand jury decide not to indict? And are grand juries only used for high-profile instances of police brutality? Let's dive into it.

What types of juries are there?

In the United States, there are two types of juries: petit (or trial) juries and grand juries.

When most people hear the word "jury", they tend to envision the former. Petit juries sit in a courtroom with a judge and lawyers present, hear a case laid out by the prosecution, and hear from the defendant. Then, the jurors decide if that defendant committed the crime as charged. Petit juries are the ones who decide whether a defendant is innocent or guilty; in other words, they're there to give out convictions. Grand juries, on the other hand, give out indictments (more on that later.)

Petit juries are smaller than grand juries. Per a U.S government website, petit juries consists of up to 12 people, while grand juries can have between 16 and 23 people. They're assembled the same way as petit juries, so if you ever get a notice for jury duty, it could actually be a call to serve on a grand jury. However, grand juries and petit juries greatly differ in terms of privacy. In most cases, trials with petit juries — like the trial of Minnesota police officer Derek Chauvin — are open to the public. The jurors only gather privately to deliberate.

A rally in Minneapolis on March 28 ahead of Derek Chauvin's murder trial. Protesters are holding signs featuring likenesses of George Floyd, as well as Breonna Taylor and Ahmaud Arbery. [Photo by Scott Olson/Getty Images]

In contrast, neither the public nor the media can attend grand jury proceedings. In fact, there isn't even a judge present. Grand juries only hear from the prosecution; the defendant and their attorneys do not have the right to appear before a grand jury like they would with a petit jury.

Why is the grand jury process so secretive?

Grand juries, which can be convened at the state or federal level, are set up by prosecutors to decide whether or not to formally charge a person with a crime. If they do hand down charges, that's what makes up an indictment. In theory, grand jury proceedings are more secretive to protect the jurors from intimidation. But this secrecy is also part of why prosecutors prefer to use grand juries even when they aren't required to; nobody else will know what the prosecutor says or presents in that room.

A prosecutor doesn't necessarily have to convene a grand jury every time they want to charge someone with a crime. According to the Department of Justice, while many states do utilize grand juries, only the federal government is required to use them, and only for felony crimes, such as embezzlement. Federal misdemeanors, like theft of public property or possession of a controlled substance, are another case — the federal government doesn't need a grand jury for that.

If a grand jury fails to indict, prosecutors can try appealing to a judge. There is one reason grand jury indictments can be easier to get than petit jury convictions, however: While a petit jury must decide unanimously to convict a defendant, a grand jury only needs a majority to indict somebody. In fact, when former New York Court of Appeals Chief Judge Sol Wachtler was an associate judge, he reportedly joked that a prosecutor could "get a grand jury to indict a ham sandwich."

And yet, when it comes to police killings, grand juries have been consistently reluctlant to indict.

What is the origin of the grand jury?

Grand juries are old as hell. According to NPR, grand juries were first recognized in the Magna Carta, the English legal charter, in 1215. They're also mentioned in the Fifth Amendment which states that "no person shall be held to answer for a capital, or otherwise infamous crime, unless on a presentment or indictment of a grand jury."

Fun fact: per the DOJ, a Supreme Court interpretation of this passage is the reason the federal government is required to utilize grand juries for felony charges, while states are not.

If a grand jury indicts someone, is that person guilty?

Let's say we spend all this time fighting for a grand jury indictment in the instance of a police killing. If we get one, does that mean the officer is guilty and will be sentenced? Nope.

Like we said earlier, grand jury indictments shouldn't be confused with convictions. An indictment simply means that the case can move forward to a trial — which is where the petit jury comes in. The latter jury (or a judge, in the case of a bench trial) then delivers the actual conviction or acquittal.

That said, a grand jury's failure to indict doesn't mean that's a wrap on the case. The prosecutor can appeal to a judge for an indictment. Remember, though, that there are levels to the legal system. A person can face both federal and state charges at the same time, but those charges will be tried in different courts; all federal charges are handled in federal court districts. So, you can be waiting on a grand jury decision at the federal level while the state says, "Eh, forget that. For our charges, we're moving ahead with a trial."

Take Chauvin, the former Minneapolis police officer facing murder charges for the death of George Floyd, as an example. The DOJ has assembled a federal grand jury to investigate Chauvin at the federal level and determine whether Chauvin violated Floyd's constitutional rights. But that jury has yet to make a decision on potential charges.

Meanwhile, Chauvin is currently on trial in state court, where he's facing charges in Minnesota of second-degree murder, third-degree murder, and manslaughter.