Howard Roffman was a researcher who, at the age of 22, wrote the book, Presumed Guilty, which argued that Lee Harvey Oswald was innocent. Here is a profile of Roffman from People Magazine from November 1975.
And here is the excerpt from Mark Lane and Dick Gregory's Book, Code Name "Zorro" : The Murder of Martin Luther King, Jr:
My favorite part of this memo is where they quote Yale Law Professor Alexander Bickel, who concluded that: "Great trial lawyers, like great detectives, have an instinct for the jugular; Mr. Lane has an instinct for the capillaries."
Substantively, the CIA memo is pretty good. I know many people will go ballistic over this post - note that the first page of the memo specifies that "we do not recommend that discussion of the assassination question be initiated where it is not already taking place."
Any organization falsely accused of heinous crimes would want its employees to be able to counter conspiracy nonsense.