He is a fan of buses and trains, wears a beige anorak, scarf, woollen gloves and clutching a nylon shopping bag with a set of keys taped to the handle.
E.g. an officer can stop or arrest people, or look in a shopping bag for lifted items, or (on authorization of the assistant prosecutor) search a home for arms.
The booster bag can be an ordinary shopping bag, backpack, pocketed garment, or other inconspicuous container whose inside is lined with a special material, typically multiple layers of aluminium foil.
