Short confirmed the news on CNN’s OutFront, telling host Erin Burnett: “I can confirm that I did receive a subpoena for the federal grand jury, and I complied to that subpoena. But under advice of counsel, I really can’t say much more than that.”
As a House committee continues to look into the events of that day, a federal grand jury is also hearing testimony related to the riots and to efforts by Donald Trump and his allies to overturn the 2020 presidential election. CNN reports that Short testified before the House committee back in January, while his testimony to the grand jury came just last week.
The New York Times reports that Greg Jacob, who served as Pence’s counsel, also testified before the grand jury — an indication that the Justice Department’s criminal investigation into Jan. 6 is intensifying.
Tensions between Pence and Trump spilled over into public view shortly before the rioters breached the Capitol that day, with Trump pushing Pence to overturn the results of the November election in his favor, after numerous legal attempts to contest the results failed in courts across the country.
In a rally held near the White House on Jan. 6, Trump grew increasingly vocal in his demands while speaking to his supporters.
“Mike Pence, I hope you get to stand up for the good of our Constitution and for the good of our country, and if you’re not, I’m going to be very disappointed in you,” Trump said.
Instead, Pence released a lengthy statement breaking with the president, just moments ahead of a joint session of Congress to ratify the electoral vote.
“It is my considered judgment that my oath to support and defend the Constitution constrains me from claiming unilateral authority to determine which electoral votes should be counted and which should not,” the statement read.
As Pence’s statement was released, the vice president and congressional lawmakers began to gather in the House of Representatives chamber to begin the counting of Electoral College votes.
Roughly an hour into the process, Trump’s supporters outside had overpowered police and forced their way into the building in a scene that eventually led to the deaths of four people as well as the evacuation of Congress and the vice president himself, who was whisked to an undisclosed location.
Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer.
Trump, meanwhile, took to Twitter to single out Pence, writing that he “didn’t have the courage to do what should have been done to protect our Country and our Constitution.”
Footage of the rioters would later show some of Trump’s supporters shouting “Hang Mike Pence” — a cry that Trump allegedly endorsed, according to those who have testified under oath about the events of that day.
Trump himself told ABC News’ Jonathan Karl that the chants about hanging Pence were “common sense” because “the people were very angry.”