More information regarding how the Warren Commission prepared for their independent investigation. From “History Will Prove Us Right” by Howard Willens, page 70
Rankin never wavered in his determination that each team should assess everything that was currently known, from every source, before marching into the field to do further investigating. At the staff meeting a few days later, Rankin set a deadline of February 10 for the comprehensive memo from each team that would summarize the known facts in its area. Redlich complained it wasn’t enough time, citing the voluminous investigative reports from the FBI and other agencies. Redlich had probably read more of these reports than the rest of us because he had been assigned to prepare for Marina Oswald’s testimony. He made the point that future critics would not excuse any failings by the commission on the grounds that it hadn’t had sufficient time to do the job. Most on the staff agreed. Rankin pushed the target date back to February 18. 23
23. Author, memorandum for the record, January 29, 1964, “Staff Meeting-January 28, 1964”, Author’s personal files.
Again, the Warren Commission did not just rubber-stamp the FBI’s reports but conducted their own independent investigation.