The guy was likely filming because he wanted there to be proof of the simple citizens arrest, not to document a murder. If you were planning on committing a murder, why the hell would you ask a friend to come tape it? THINK!
Guess it didn't work out for the third killer, eh? The sound of the driver loading his gun can clearly be heard on the video. This was a setup. Criminal and premeditated. Yes, they may have thought they this guy would be compliant to their illegal request, but he wasn't. Why are you still defending these scumbags?




