How to Be a Serial Killer (2008)

Mike is your typical motivational speaker promoting self help through a series of lessons. But what's different about Mike is he's a serial killer and he wants to teach you to become one as well.

Mike encounters the downtrodden Bart, a video store clerk, as Bart is being berated by an obnoxious customer.  Mike sees a perfect student to learn his skills, and takes Bart under his wing to teach him how to kill and not get caught.

On the surface, Mike appears to be a happy guy living a normal life. He's got a job, is an attention considerate boyfriend, and lives with his girlfriend Abigail.  But that's part of Mikes charm and method of blending in, since a happy girlfriend won't question things that might not make sense and will help provide the perfect cover.

Surprisingly Bart is on board with with Mike's offer as he's tired of being pushed around.  So the two start spending lots of time together so Bart can study his methods, learn the rules, and eventually start killing on his own.

This is a dark comedy which covers similar ground to Man Bites Dog.  Matthew Gray Gubler is perfectly cast as the emotionally injured and vulnerable Bart.  Part of the film is done documentary style where the characters talk to the camera as if they're being interviewed.  But unlike Man Bites Dog, this has a more comedic feel and is not as dark, violent, or disturbing.