Ok I think we are getting real close I have an issue with the order of clauses in the first line The current wording gives too much weight to Oswald being the assasin as a firm fact vs being identifiedfound as the assassin Compare to Ruby as the killer of Oswald that was caught on film redhanded  Lee Harvey Oswald    was the assassin of US President John F Kennedy according to four US government investigations into the assassination  How about    Lee Harvey Oswald    was according to four US government investigations the assassin of US President John F Kennedy    or  According to four US government investigations Lee Harvey Oswald    was the assassin of US President John F Kennedy