A federal grand jury has been meeting to decide whether to bring charges against former President Trump in connection with the transfer of power following the 2020 election and the Jan. 6, 2021, Capitol riot.

But what is a grand jury?

Before unveiling felony charges in federal court, prosecutors must present evidence to grand jurors and receive their signoff.

Federal grand juries comprise between 16 to 23 people, and at least 16 must be present for a quorum. In this instance, the jurors are all residents of Washington, D.C. They have been meeting behind closed doors in a courthouse just blocks from the Capitol and White House.

Prosecutors have brought in numerous witnesses from Trump’s orbit to testify.

Ultimately, the proceedings wrap up with the grand jury taking a vote on prosecutors’ proposed indictment. 

Recent signs suggest the indictment vote could be close. Trump has said he received a target letter from the Justice Department more than two weeks ago that gave him the opportunity to testify before the grand jury, a step that usually occurs when prosecutors are nearing a final charging decision.

At least 12 jurors must vote in favor of the indictment for it to be returned, known as a “true bill.”

Grand jurors are asked to decide whether there is probable cause to believe the person in question committed a crime. It’s a much lower standard than prosecutors would need to prove at trial: proof beyond a reasonable doubt. 

What charges prosecutors are considering remain unclear. If the grand jury votes to return the indictment, in D.C. it is generally received by the duty magistrate judge and placed under seal.  On Tuesday, Judge Moxila Upadhyaya is scheduled as the duty magistrate. A different judge would oversee the trial.

In the classified documents case filed in Florida, prosecutors moved to unseal the charges ahead of Trump’s first court appearance. It remains unclear when the charges would be unsealed in the Jan. 6 case.