The mood of this image is suspenseful because of the diagonal angle the camera is being held. How the lighting is hitting the mans face underneath him seems to give him power and more focus. Over the man closest to the camera and the shot is an over the shoulder giving more attention of the man in focus. I’ve noticed there are 3 light sources, a key, fill and background light. Which all are facing the man. Overall the shot composition is very well done and has many elements contributing other than a gun in the mans hand.