CNN is also reporting for the first time that the committee subpoenaed Short a few weeks ago.

Short remains one of Pence’s closest advisers and is a firsthand witness to many critical events the committee is examining, including what happened to Pence at the Capitol on January 6 and how former President Donald Trump pressured the former vice president not to certify the presidential election that day.

Short’s assistance signals a greater openness among Pence’s inner circle. One source told CNN the committee is getting “significant cooperation with Team Pence,” even if the committee has not openly discussed that. Another source told CNN that Short’s help is an example of the “momentum” the investigation is enjoying behind the scenes.

Last month, CNN reported that a number of figures close to Pence, including Short, may be willing, either voluntarily or under the guise of a “friendly subpoena,” to cooperate with the committee.