To cope with these stressors, the logical faculties of the victim's conscious mind are suspended and behavior becomes purely survival-oriented. Since these stressors damage the psyche and lead to quantifiable ideational and behavioral changes specifically characteristic of rape victims, the behavior is difficult to understand without expert interpretation. Recognition of the rape trauma syndrome as a specific type of anxiety disorder classified as posttraumatic stress disorder is essential in rape investigation. Police investigators who are cognizant of rape victims' stress reactions will be more effective in conducting followup investigations and collecting additional evidence. By showing concern for the victim's feelings and reactions, they will reduce some of the associated trauma and encourage fuller cooperation during subsequent prosecutions. Techniques for interviewing rape victims include careful attention to the victim's directly observable trauma symptoms. In addition, an investigator should be alert for psychological lifestyle changes of the victim. The rape trauma syndrome and other psychological evidence has been useful during trial; expert testimony may be admitted for explanation of the psychological aspects of rape. Criteria necessary to substantiate the rape trauma syndrome include reexperiencing the trauma caused by various mental or physical stimuli. Other psychological symptoms of trauma may be experienced by the victim, and a police investigator familiar with psychological principles may be able to help the victim. Twenty-six footnotes are provided.