The authors explain that in most circumstances, criminals give hints of their criminal intentions before they carry them out. Close observation of people’s behaviors can alert others to a potential problem. According to the authors, investigators can use the UPCB model to analyze behavior that may signal impending criminal actions. The UPCB model claims that actors go through four stages in committing a criminal act: ideation, communication, facilitation, and actualization. Ideation is the process of forming the idea of the intended criminal act. As people think about certain things they give off verbal, non-verbal, physiological, symbolical, and behavioral clues about what they are thinking. An astute observer may be able to thwart a crime at this stage by picking up on the offenders’ subtle cues. The second stage, communication, involves the subtle or straightforward conveyance of the offenders’ thoughts. Examples of communication include tattoos signaling hatred for certain groups or subtle eye movements that indicate lying behavior. Facilitation is the third stage of the UPCB model and it involves actions taken by the offender in preparation for the crime, such as purchasing a gun. The final stage is actualization, in which the crime is actually carried out. The author explains that officers should be familiar with these stages of criminal behavior in order to thwart criminal intentions before they are carried out to completion.