As you explain this horrific story, an envelope is handed to your spectator to hold. Next, 10 photos are introduced. It is explained that the killers are lost amongst the victims and it is down to your spectator to separate the living from the dead. 5 photos are handed to your spectator and 5 are kept by the performer. The spectator is instructed to hold the photos behind their back and slide one photo from the top to the bottom. They must keep doing this until they get a feeling, whatever feeling that may be. Once they are satisfied, they are to remove the top photo and hold it behind their back being sure never to let go of it. The performer does the exact same behind his back.
The remaining photos are exchanged between the performer and spectator. She is then instructed to place her photo in so that it is faced the opposite way to the other pictures and to mix them. Again, the performer also does this. Both stacks of photos are brought out and both the performer and spectator have one single photo turned, sight unseen the other way.
The envelope is brought back into play and the spectator tips out what is inside. Two photos are removed. That of a man and a woman. The killers. And although the spectator did not let go of their selection for a single second, and they have an undeniable account of what has happened, they slide their selection from their stack of photos and reveal it to be the same killer found in the envelope. The performer then does the same and is found to have selected the second killer.
But if all of this is true, then we would need evidence that those in the envelope really were the killers. At this time, the photos from the envelope are turned over to reveal the words KILLER scratched in blood red on the back of them. And every other photo? They have DEAD etched in blood on the back of them. Everything is examinable and the reset is instant.
TWO CARDS. ONE DECISION. LIE OR TELL THE TRUTH.