The House Jan. 6 committee announced an previously unplanned hearing for June 28, promising new evidence and witness testimony.

Committee members did not confirm a focus for Tuesday’s hearing, scheduled to begin at 1 p.m. ET. But it will likely lean heavily on the testimony of Cassidy Hutchinson, a senior aide to former Trump chief of staff Mark Meadows, the NewsHour and other media outlets confirmed.

In the course of her work for the White House, Hutchinson had firsthand insight into communications between Meadows and former President Donald Trump, including those leading up to the insurrection and in the days afterward.

In the year since its creation, the committee has conducted more than 1,000 interviews, seeking critical information and documents from people witness to, or involved in, the violence that day.