This acute catathymic crisis contrasts with the chronic form, which may last from several months to more than a year, that has three basic stages: incubation, violence, and relief. In the acute form, situational and interactive components are important, but the act cannot be explained without an exploration of the offender's personality structure. The 12 cases include a sudden, unprovoked attack on a pregnant woman in plain daylight in a bus station, an unprovoked stabbing of a store employee by a 15-year-old male who had come to the store to pick up newspapers for delivery, the sudden murder of a 7-year-old girl who had rung the doorbell to sell cookies, and the shooting of a date while riding in her car. The cases show that most sexual assaults are a sexual expression of aggression, that offenses have strong situational elements, and that offenders' mental disorders varied in their manifestations.