 Unfortunately for him, Calleigh notices the void when she comes to photograph the scene, and Hagen comes up from behind, pulls his gun on her, and flees.Though at the time she does not know that he is the perpetrator, she remembers vividly the sound of the gun cock, and recognizes it moments before Hagen commits suicide in the ballistics lab.She finds the missing evidence in his jacket pocket as the coroners wheel out his body.