This chapter addresses a method for identifying the primary suspect in a murder investigation, which has proven to be especially beneficial when undertaking a cold case evaluation. This method requires evaluating the information pertaining to pre-crime events, the facts of the crime, and post-crime behaviors, and is wholly comprehensive. As such, the primary benefit to cold case evaluators is this: At the onset of a cold case evaluation, investigators have the advantage of having all relevant case information available, whereas during a hot case they must rely on a trickle of incoming information. This process is started by first examining the core elements of the crime where a subtype is identified and subsequently moves outward from a working premise toward identifying like characteristics in identified persons of interest.