http://karws.gso.uri.edu/JFK/the_critics/griffith/Why_Tippit_stopped_Oswald.html>>>>snip
One of the most unlikely, implausible aspects of the Warren Commission's lone-gunman scenario is the assumption that Officer J. D. Tippit stopped Lee Harvey Oswald on the basis of the description of the alleged assassin that had been broadcast by the Dallas Police Department. It is doubtful that Oswald could have even reached the crime scene in time to shoot Tippit. It is equally doubtful that he could have arrived in time to have been casually walking along the street just before Tippit supposedly approached him and stopped him. But leaving aside these problems, one is struck by the implausible nature of the Commission's story of why Tippit would have stopped "Oswald" in the first place. Henry Hurt explains:
One of the oddest assumptions of the Warren Commission was that Officer Tippit stopped Oswald because he was able to identify him as the man described in the police broadcasts that started about 12:45 P.M. According to an FBI statement to the commission, the source of the original description was "an unidentified citizen." The description provided by this citizen (later assumed to be Howard Brennan) was for a man "running from the Texas School Book Depository immediately after the assassination."
The description itself was of a "white male, approximately thirty, slender build, height five feet, ten inches, weight one hundred sixty-five pounds" and believed to be armed with a .30-caliber rifle. This description missed Oswald by six years and about fifteen pounds, yet the Warren Commission reasoning accepted as fact that based on this description Officer Tippit stopped Oswald. (Reasonable Doubt, New York: Holt, Rinehart, and Winston, 1985, p. 163)
The more one thinks about it, the more one realizes how extremely implausible and unlikely this scenario is. Why would Tippit have stopped Oswald? The police description could have fit a good quarter to a third of the male population of Dallas. "Oswald," or whoever it was, was some three miles from Dealey Plaza, walking in a quiet suburb when he was supposedly stopped by Tippit. None of the witnesses who saw Tippit's assailant just before Tippit stopped him said the man was walking unusually fast or in any way acting strange or suspicious. What's more, Tippit, though apparently well liked by his peers, was not exactly a zealous or above-average policeman. In fact, he hadn't been promoted in ten years. So why would Tippit have stopped Oswald?