Some more from “History Will Prove Us Right” by Howard Willens, page 100:
Because Rankin had required that all investigative requests be reviewed by me before going to him for approval, I had more dealings than others on the staff with James Malley, the FBI inspector who was our official liaison with the bureau. There were approximately three hundred such investigative requests, most to the FBI. On occasion, Malley discussed a particular request with Rankin or me (or other lawyers) and suggested ways to rephrase or break it down into more limited requests. We almost always agreed to make these suggested changes. If the responsible lawyer and Malley could not agree, Rankin would resolve the issue. Malley described his relationship with the commission as businesslike, and I agree with that. He knew that I worked for the Justice Department and had access to high officials there. I knew that he had superiors at FBI headquarters who insisted that he keep them fully informed about the commission.
The commission’s lawyers weren’t hesitant about questioning the FBI’s work. They understood that they had been appointed from the private sector in large measure to ensure their independence in conducting a thorough investigation. In fact, they relished proving FBI conclusions wrong. Most of our lawyers focused on finding flaws in the FBI conclusion that there were no conspiracies involving Oswald or Ruby. Many likely thought that someone (or some organization) more able and intelligent than Oswald and Ruby might have had a hand in this national tragedy and that this possibility had to be fully investigated. The team worked hard to examine every possible angle from which a conspiracy might have arisen. Conspiracies are almost always eventually revealed. No one on the staff wanted to go down in history as among those who failed to uncover the conspiracy that had taken a president’s life. None of us regarded the FBI denial of conspiracies involving Oswald or Ruby as established fact.