Donald Trump’s former top adviser, Stephen Miller, testified before a federal grand jury on Tuesday as part of the Jan. 6 criminal investigation led by the Department of Justice. The former speechwriter spent several hours at a federal court house in D.C., where lead prosecutor Thomas Windom was also spotted, according to CNN. Miller is the first known witness to testify before the DOJ-appointed special counsel, who was appointed earlier this month to oversee investigations into the insurrection and classified documents Trump took to his Mar-a-Lago home. As part of an entirely separate investigation, Miller testified virtually before the House select committee in April regarding the events of Jan. 6. In a public hearing in July, that committee revealed that Trump insisted on keeping lines targeting ex-Vice President Mike Pence in his speech at the Ellipse, despite pushback from White House lawyer Eric Herschmann, and hours before rioters would storm the Capitol chanting, “Hang Mike Pence.” The DOJ also requested Pence’s testimony last week.