The authors examine the prevalence of acute traumatic dissociative responses in a group of 115 law enforcement officers involved in critical incidents. Law enforcement officers were retrospectively surveyed for the presence of dissociative symptoms at the time of the critical incident, as well as for the presence of acute stress symptoms and posttraumatic stress symptoms. Results show that 90% of the officers reported experiencing a dissociative response during the critical incident. Thirty percent meet the Dissociative Criterion B of acute stress disorder under the DSM-IV. The mean number of dissociative symptoms in this group was two and one-half. In addition, 19% of the law enforcement officers reported varying forms of memory impairment for details of the incident. There were no reports of amnesia for the entire event. The clinical, forensic, and legal implications of these preliminary findings are discussed in this paper.