The difficulty for the committee in tracking down just whom Trump spoke with — and when — is dealing with his unorthodox phone habits while in office: According to multiple sources formerly in the administration, the ex-President often used other people’s telephones (or multiple phones of his own, sometimes rotated in and out of use) to communicate with his supporters — and even family.

One former staffer blamed the former President’s habit on an aversion to anyone listening to his calls (which, in the White House, is hard for a president to avoid if he calls from a desk phone). So he would, frequently, grab the cell phone of a nearby aide or even a Secret Service agent to make calls.

One case in point: After the Stormy Daniels story broke in 2018, Trump was on the golf course trying to reach his wife, Melania Trump, from his phone, and she did not pick up, according to a source with knowledge. So he turned to a Secret Service agent and used the agent’s phone to try to reach her instead. The first lady then picked up. According to this source, the agent was not pleased his phone had been used this way.