Former senior White House official explains how to resolve Trump's mysterious 7-hour call gap on Jan. 6

Writing for Rachel Maddow's blog, former litigator Lisa Rubin explained that she spoke with a former senior White House official about being able to find the missing seven-hour lapse in phone calls from former President Donald Trump on Jan. 6.

First is the presidential "daily diary," which is a list compiled by a full-time staff person and others who contribute details about everything the president has done throughout a day.

"The diarist depends on the people in closest physical proximity to the president for the information included in each day’s entries," Rubin described. "White House staffers who typically contribute to the diary include the president’s personal aide (also known colloquially as his 'body guy'), the president’s personal secretary, staff of the WH Communications Agency or Situation Room if the president speaks with a foreign leader, and/or the head of Oval Office operations. Depending on the staff secretary’s relationship with the president, that person may be involved as well."

Stephanie Grisham has already reported that she witnessed Trump "gleefully" watching parts of the Jan. 6 attack on the television in his personal dining room. It's possible, Rubin explained, that Trump made calls from a "burner phone" there.

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There's also a "peephole" in the door to the Oval Office, so the president's personal secretary can check if the president is on the phone or otherwise occupied before entering the room. So, it's possible that the personal secretary may have witnessed calls made.

The former official told Rubin that they should interview Trump's personal secretary, personal aide and diarist, although two of those have already been subpoenaed.

In a report from The Guardian, there are several current and former White House officials who explained that Oval Office aides “have some sway to determine whether a particular event was significant enough to warrant its inclusion" on the log list. By contrast, "the presidential call log, typically generated from data recorded when calls are placed by the White House operators, is supposed to be a comprehensive record of all incoming and outgoing calls involving the president through White House channels."

The daily diary and call logs must then be approved by a senior White House official before being sent to the office of records and management. It ultimately means anyone in the Trump hierarchy could edit the calls.

It was also reported this week that the phone call from Trump to Sen. Mike Lee (R-UT) came from another White House phone number that isn't tied to the president's office. It would mean that Trump made the call from another office that wasn't being tracked by the switchboard, placing the president's calls. It would give a justification for the House Select Committee investigating Jan. 6 to subpoena all call information from all of the West Wing on Jan. 6.

Read the full piece from Lisa Rubin at MSNBC's Maddow Blog.