On August 22, 2017, Simpson was questioned for 10 hours by the Senate Judiciary Committee in a closed-door meeting. The Committee did not release a transcript of the hearing, but indicated that Fusion GPS had given more than 40,000 documents for the investigation. Simpson kept the identities of the firm's clients confidential; the client names—conservative website The Washington Free Beacon, and the law firm Perkins Coie representing the DNC and the Clinton presidential campaign—were revealed in October 2017 as a result of the House Intelligence Committee investigation.
