The magician places 3 Jacks in a deck, which he tells the audience are robbers. He places a Jack on top of the deck, one in the middle, and one at the bottom. The magician then places a King, which he says represents a cop, on the bottom of the deck. Magician asks a spectator to cut the deck. The magician explains that the deck of cards is a bank. When the deck has been cut, the magician takes it, and looks through it to show that the three Jacks (robbers,) are together with the King (cop.) The cop caught the 3 robbers that tried to rob the bank.
This trick requires preparation before performing it. Before performing, the magician secretly places a jack on the bottom of the deck. He does not let anyone see this.