Two sources familiar with the move told CNN that Rigelman’s upcoming exit was “amicable.” Rigelman sent a letter to the President and Vice President informing them of his decision. In the letter obtained by CNN, he wrote that his “initial work has been completed” for the commission.

“I sincerely hope that this commission will be able to issue a fact-based report on those responsible for January 6th, and outline processes and policies to prevent such activities in the future,” he wrote. The importance of the commission cannot be overstated.”

Riggleman is a disinformation expert and was a senior technical advisor who worked with a team examining data the commission was taking as part of its investigation. This work will continue after he leaves.