Staging a murder is both a clever experiment and a cruelly funny prank

How do everyday people react when they stumble on a murder in progress? That's the question posed by this video, devised to promote upcoming thriller "Dead Man Down." A camera is hidden inside a New York City elevator, in which one actor pretends to strangle another with a rope as the doors open. Some onlookers scream, some rush to help, while others rapidly back away from the scene like it's a bad smell and not a potential homicide. But the most concerning reaction belongs to the very last guy in the video, who responds to what he's seeing in a disturbingly modern fashion.

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