CarolC's theory that they followed him for a long time to get a big audience when they killed him is interesting. So how many people were actually watching in that carriage on the tube? Would this really be the most populous place in London? I am not an experet on London(perhaps CarolC is) but I can think of better places to get a big audience than inside a carriage on the tube.
    And, please, the old canard is so popular now, "the wicked police made up a lie about his bulky jacket to justify killing him". Now, this is a murky story, but surely it is obvious to anyone(except the usual suspects green lizard brigade) that this this description came from an eye-witness that was passed to the press and widely circulated. It may have been total bollocks(presumably he confused the victim with an officer in a flak jacket), but it was "evidence"(ie: what a witness claimed). Absolutely not a police fabrication.