http://en.wikipedia.org/wiki/Snuff_102_(film)
I hired a movie from a video rental shop one day - meant to be a comedy - the video tape inside didnt match the title and on watching it, it consisted of a woman being molested and strangled. I will swear to this day I saw a real life snuff situation going on - the light extinguishing in the girl's eyes was enough for me to turn it off and straight back to the store.
Maybe I should have investigated further but I was just glad to give it back!