For the purposes of this study, "stalking" is defined as "the act of following, viewing, communicating with, or moving threateningly or menacingly toward another person." This article presents the deductive process used to devise the Stalking Incident Checklist and reports the findings of a sample of 30 cases as a typology of stalkers based on the nature of the relationship (nondomestic or domestic), content of communication (nondelusional or delusional), level of victim risk in terms of offender aggression (noncontact or physical contact), and outcome (court, psychiatric, not reported, suicide). Using a law enforcement experiential paradigm, 10 stalking victims pilot- tested a questionnaire of 148 items. Revisions provided a 46-item checklist. The authors conclude that by using the stalking- incident form, clinicians can classify stalkers by the nature of the relationship, content of communication, level and escalation of aggression, and risk-level to the victim. Risk level to the victim increases with an increase in the amount of stalking incidents, detailed knowledge of the victim, sexual comments, show of weapon, threats to injure, and delusional content. An increase in stalking behavior can be sudden. All stalking victims are at risk for personal safety. Data on stalking behavior can provide information on patterns of violence and assist law enforcement agents, prosecutors, and judges in decisions regarding bail, restraining orders, and other case processing. Further research is necessary to differentiate the motives involved in stalking. 1 table and 29 references