Pence chief of staff alerted Secret Service of risk to Pence on eve of Jan. 6

The day before the Jan. 6, 2021 attack on the Capitol, the chief of staff to then-Vice President Mike Pence warned the Secret Service that there could be a potential threat to the vice president, CBS News has learned. 

On Jan. 5, Marc Short called the lead Secret Service agent Tim Giebels, warning him of the potential threat to the vice president without being specific about the nature of the threat he anticipated. This was the first time that Short had ever notified the Secret Service of a potential threat, and it was the result of an assessment by Short that then-President Trump would publicly turn against Pence. The New York Times first reported Short's warning to the Secret Service. 

Short expects to be one of the witnesses appearing before the House select committee investigating the Jan. 6 attack, as public hearings get underway this month. The exact date of his appearance has not been announced. 

Typically, the agency dedicated to protecting the vice president was the one sharing the risk assessments. Short's assessment was general, CBS News has learned. He did not have evidence of a specific plot. But Short knew that Trump was trying to intimidate Pence into stopping the certification of the Electoral College count, and that the vice president had no intention of doing so.

Short will undoubtedly be questioned about the events of those fateful days when he publicly testifies. He will also likely be asked about interactions with his White House counterpart Mark Meadows, who was Trump's chief of staff.

Text messages from Meadows, which have been reported by CBS News and other news organizations, show he was in contact with various actors who supported efforts to keep Trump in office in the days leading up to Jan. 6. Yet, at the same time, Meadows was privately assuring fellow White House officials and then-Senate Republican leader Mitch McConnell that he was urging the president to concede the loss. 

Short met with the House select committee on Capitol Hill in January.

Short was with Pence in the Capitol on Jan. 6 as pro-Trump rioters overtook the building, and the pair were forced to evacuate to a safe location within the Capitol complex. Trump had publicly and privately pressured Pence to reject the election results in certain states won by Joe Biden, but Pence issued a statement saying he could not do so.