The term "catathymic" process was originally coined by Maier (1912) as a derivation from the Greek "kata" and "thymos," which is best translated as "in accordance with emotions." Wertham (1937) was the first to use the concept of catathymia to explain homicides that stem from strong, underlying, emotionally laden conflicts that result in a change in thinking, so that the future offender acquires the obsession that he must carry out a violent act. Revitch and Schlesinger (1981, 1989) updated Wertham's "catathymic crisis" by conceptualizing the syndrome as a psychodynamic process with the following three stages: incubation, violent act, and relief. During the incubation period, which may last from several days to even a year, the future offender becomes obsessively preoccupied with the victim. He develops the idea that he must carry out a violent act against someone he professes to love, such as a current or former girlfriend, a parent, or even his entire family. This concept is applied to an actual case in which a man stalked and killed a casual acquaintance. He developed an idea to kill her that, at first, seemed ego-alien and unreal, but eventually became fixed and was accompanied by a mounting inner pressure to act. The recognition of the clinical manifestations of the catathymic process, especially when a stalker reveals ego-dystonic homicidal ideas as a solution to his plight, helps to identify an individual at great risk. Accordingly, to discern the presence of developing homicidal thoughts and fantasies, clinicians, police, and other investigators should routinely ask stalkers pointed questions about their thinking. 47 references