retro - // I am not struggling with anything except I can't recall how he knew and recognised all the gang members when he didn't witness the crime? //
The criteria for 1970's vigilantes in film to annihilate at will any person or persons deemed by appearance to be unreasonably depleting the planet's oxygen resources are clear and include, but are not limited to -
wearing unacceptably casual clothing, including inappropriate footwear, being trainers or biker boots etc.
wearing any kind of necklace or personal jewellery
wearing hair in any sort of challenging style and / or length
adopting an appropriately unconcerned attitude to the world in general, such as a sneer, a frown, or just generally looking at the vigilante in a funny way
talking in a foreign accent
being of foreign appearance
chewing gum
drinking in public, or in private
glancing for more than half-a-second at any female in the vicinity
being under twenty-five.
Hope this helps.