Howard Brennan's work supervisor, Sandy Speaker, told Jim Marrs that federal agents applied enormous pressure on Brennan to ID Oswald as the man he'd seen in the sixth-floor window:
Brennan’s job foreman, Sandy Speaker, told this author:
They took [Brennan] off for about three weeks. I don’t know if they were Secret Service or FBI, but they were federal people. He came back a nervous wreck and within a year his hair had turned snow white. He wouldn’t talk about [the assassination] after that. He was scared to death. They made him say what they wanted him to say. (Jim Marrs, Crossfire: The Plot that Killed Kennedy, Basic Books Edition, revised and expanded, p. 25)