I suppose this sort of dumbass stunt could only take place in New York City . . .
As part of an ad campaign ... NYC-based marketing firm Thinkmodo decided to see what New Yorkers would do if they happened to stumbled onto a crime in progress — namely, a murder.
The agency set up a camera inside a nondescript New York City elevator, and filmed the reactions of unsuspecting marks as they encountered a man strangling another man to death with an extension cord.
Not surprisingly, many passers-by chose to bolt rather than take any immediate action, though some tried to help ...
There's more at the link.
I'm glad they didn't try to do that in the city where I live, or in most of the southern and central USA. If a lot of folks round here walked in on what looked like a murder in progress, there would indeed be a death - that of the perpetrator, who'd be ventilated by several bullet holes without further ado! I suppose they figured that in New York City, none of the good guys would be armed anyway, thanks to that city's draconian firearms restrictions - and any armed bad guys would be more likely to nod, wink, and tell them to carry on.