Most notably, the federal grand jury in Washington that has already indicted two key Trump associates is continuing to meet and hear more evidence from prosecutors. The grand jurors’ identities are unknown, but their faces are recognizable to the reporters and producers who have been standing inside the courthouse each week. Just a week ago, one of Mueller’s top prosecutors, Jeannie Rhee, was spotted at the courthouse by ABC News.

In October, the grand jury in Washington indicted Trump’s former campaign chair Paul Manafort and Manafort’s former business partner and Trump campaign aide Rick Gates for alleged money laundering and other financial crimes involving their now-defunct international consulting business.

Mueller became special counsel seven months ago, and he began using the grand jury in Washington shortly thereafter. Such grand juries often last for up to 18 months, and they can be extended for six months at a time.