Most of these are literally based on movies, as I read somewhere. Automatic knives were common accessory of a villain in the movies of the period. Movie silence

Most of these are literally based on movies, as I read somewhere. Automatic knives were common accessory of a villain in the movies of the period. Movie silencers allow you to shoot in a library undetected. Others are likely a misclassified "the shoulder thing that goes up" (from Predator?)