Critical Incident Interviews: 48-Hour Delay Still Good Advice?

by | June 19, 2020

Originally published on the Force Science Institute website. Republished here with permission.

Following a high-intensity event, should officers be allowed to recover before being interviewed?

In 2014, Dr. Bill Lewinski, executive director of the Force Science Institute, sat down with Force Science News1 to explain why he recommends a 48-hour minimum recovery period. “This is the general conclusion from some 20 years of scientific research on sleep and memory consolidation. And it is the position supported by the Police Psychological Services Section of the International Association of Chiefs of Police.”

But is the 48-hour minimum recovery still good advice?

Critics argue delayed interviews are unnecessary, and transparency and police accountability demand immediate interviews of those involved. Dr. Lewinski disagrees: “A robust body of literature and the clinical experience of psychological and criminal justice professionals informs us that survivors of traumatic events can have difficulty recounting many of the elements of the incident.”

Despite advances in science, there are those who continue to ignore the effect of stress and trauma on memory formation.

Dr. Lewinski explains: “Survivors of traumatic events aren’t just witnessing the event; they are experiencing it, and this experience can significantly affect brain function and memory. Although every shooting is unique, confronting someone you believe is trying to kill you can be a significant emotional event. During these events, survivors may not consciously choose what to pay attention to. Instead, they tend to focus on the elements of the incident that were most important to their survival rather than the elements that may be important for investigation and prosecution.

He continues, “The best investigators recognize the relationship between emotions, attention, and perception. They understand how these processes can affect encoding, consolidation and, ultimately, memory. Even subtle factors can significantly influence memory storage. For example, the order in which we ask questions can inadvertently attach significance to that information. When someone has been involved in an emotional event, the first questions asked may be perceived as more significant, which impacts how that information is encoded and stored.”

Dr. Lewinski is impressed by advances in law enforcement investigative practices. “Law enforcement has developed some sophisticated and clinically relevant procedures for mining the memory of someone involved in an emotionally distressing incident. As part of these protocols, delayed interviews do more than just take advantage of the consolidated memory that occurs during sleep; these delays provide temporal distance from the traumatic event and an opportunity for emotional decompression.”

He explains: “Beyond the exertion and adrenaline surge that may have occurred during an event, law enforcement is a chronically sleep deprived profession. These factors can interfere with memory consolidation and the accuracy of recall and response. Delay permits physical recovery and rest. It allows officers to return to the interview with increased cognitive clarity—resulting in a clearer understanding of the questions posed and the most complete and accurate responses.”

“Some of the researchers on memory who are attempting to influence investigations, and even some administrators and investigators, treat an officer after a traumatic event as if they calmly memorized a grocery list.”

Dr. Lewinski warns that rushing interviews can jeopardize more than just the investigation. “Interviewing someone who has been traumatized before they’ve had a chance to decompress not only affects the quality of memories but can actually create psychological injury and significantly increase the chance of a long-term traumatic disorder.”

Despite advances in science, there are those who continue to ignore the effect of stress and trauma on memory formation. He laments that “some of the researchers on memory who are attempting to influence investigations, and even some administrators and investigators, treat an officer after a traumatic event as if they calmly memorized a grocery list. This approach presumes the officer merely witnessed the traumatic event and ignores the psychological and emotional effects of experiencing trauma. This is an overly simplistic and naïve approach to sleep, stress and human memory.”

Dr. Lewinski says, “If the goal of police interviews is a search for the truth, we want our policies and practices to be backed by good science. The decision to interview an officer immediately after a critical incident or to allow a period of recovery should be based on whichever practice will result in the most accurate and complete information for that officer.”

Readers interested in the powerful impact that stress and emotion have on our memory and performance should be following the research of Dr. Jessica Payne, who holds appointments at Harvard Medical School and the University of Notre Dame. Her latest research on sleep and stress has important application to police practices and will be presented at the next Annual Force Science Conference.



1. Chuck Remsberg. “Force Science Institute Details Reasons for Delaying Interviews with OIS Survivors.” Force Science News, May 3, 2014, Accessed 22 May 2020.

2. The IACP continues to recommend a 48-72-hour pre-interview delay. See, International Association of Chiefs of Police. 2016. Officer-Involved Shootings: A Guide for Law Enforcement Leaders. Washington, DC: Office of Community Oriented Policing Services.

3. See Hope, L., Blocksidge, D., Gabbert, F., Sauer, J. D., Lewinski, W., Mirashi, A., & Atuk, E. (2016). Memory and the operational witness: Police officer recall of firearms encounters as a function of active response role. Law and Human Behavior, 40(1), 23–35., (detailing how officers who were interviewed immediately after a stressful simulation doubled their pulse when asked about the threatening elements of their incident during a follow up cognitive interview) (copies of the study can be obtained here); see also Chuck Remsberg. “New Findings About Simulation Training and The Stress of Post-Shooting Interviews.” Force Science News, December 15, 2006, Accessed 26 May 2020.

Lewis “Von” Kliem, MCJ, JD, LL.M., has nearly 30 years in the criminal justice profession and has worked as a civilian police officer, attorney, educator, and author. A former attorney with Lexipol, Von is the executive editor of the Force Science News, and is co-owner of Von Kliem Consulting, LLC, where he trains and consults on constitutional policing, use of force analysis, crisis communications, and trauma-informed interviewing. About the Force Science Institute The Force Science Institute (FSI) is comprised of a team of physicians, lawyers, psychologists, scientists, police trainers and law enforcement subject matter experts dedicated to the advancement of knowledge and training in criminal justice matters. FSI conducts sophisticated scientific research studies into human behavior documenting the physical and mental dynamics associated with the societal demands of the peace-keeping function, including high-pressure situations and use-of-force incidents. Its findings apply to citizen-involved uses of force as well as impacting investigations of officer-involved force applications. FSI research, when applied to training, enhances officer performance and public safety.

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