Geni - Catch

You are finding one trick that can perform with 2 decks of card. This trick is for you
Imagine magician show 2 decks for spectator. They pick one. And select randomly 1 card (No force), that card will mark by placing between 2 red kings.
After that the magician show the second deck, take out 2 red kings, and bring them into middle of the deck, and with just by a snap of finger, 2 red kings catch one card, and that card was same as the card that spectator choose at the first deck.