I believe its a british movie or the lead actor is british. it's a movie about a guy who goes around killing people filmed like a documentary from his POV. he uses a video store to target his victims when the hire "his" video. People watch it thinking its a movie and at the end it appears he is coming for you. it has abit of dark comedy at times. in the movie he also goes back and kills a guy he previously saved from suicide. I think it came out in the early 2000's. Hope someone can help!