Find the Burglar

This experiment is adapted from Jack Merlin's popular effect.

Two kings are moved from the deck. A card is chosen and returned to the deck, and then the deck is shuffled. First one king is placed in the deck and next to it the other one is placed, both extending about half way. Performer states that the kings are very clever detectives and a burglar could not escape them. Supposing that the selected card is a burglar, it will not take long far the kings to find him. Magician moves kings up and down. Suddenly he pulls them out of the deck and shows the selected card to be between them.