A new book's behind-the-scenes look at Congress' Jan. 6 Capitol riot investigation

Denver Riggleman served eight months as a senior technical adviser for the congressional select committee investigating the Jan. 6, 2021 attack on the U.S. Capitol. In a new book, titled "The Breach," Riggleman delves into a few key parts of the committee's investigation, including an examination of a trove of text messages sent and received by former White House chief of staff Mark Meadows in the lead-up to the Capitol riot. The book also revealed for the first time that during the Capitol breach, someone at the Trump White House made a call to a rioter who had entered the building.

Riggleman took a somewhat unusual path to the committee. After serving in the United States Air Force and working as a contractor for the National Security Agency, he ran for - and won - a seat in Congress representing a district in Virginia in 2018.

At the time, Riggleman