The author defines "police humor" as "a group of psychological mechanisms with which an individual officer or group of officers attempts to sanitize, on an emotional level, the suicide scene and its subsequent investigation, so that unpleasant to highly odious, yet necessary, tasks can be performed in the line of duty." Following a discussion of the developmental aspects of humor, the author considers how the characteristics of police suicide humor mirror an officer's general emotional development. This can range from primitive to mature. The author briefly discusses the primitive, immature, adolescent, and mature humor coping strategies used by police officers during a suicide-scene investigation. She then links the types and mechanisms of humor of the various degrees of emotional maturity into a humor cycle. This is followed by a discussion of the general and specific influences and uses of investigational humor and traces the relationship between the zones of humor and both the stage of the suicide investigation and the degree of officer experience. The author advises that the existence of and the types of humor manifested by an officer under stressful investigations can constitute warning signs that an officer needs help in managing the stress. She advises that the most psychologically vulnerable police officers are the retired officer and the young police officer who discover the bodies of loved ones or partners who have committed suicide. 1 figure