A new study has challenged the traditional practice of allowing an officer time to “cool-off” before giving a statement following a police shooting.

Recovery Time Following Shooting

Traditionally, when a police officer is involved in a shooting, the officer is given a period of time to recover before providing his or her statement. The International Association of Chiefs of Police “Officer-Involved Shooting Guidelines” recommends that “Officers should have some recovery time before providing a full formal statement… An officer’s memory will often benefit from at least one sleep cycle prior to being interviewed leading to more coherent and accurate statements.”

This recommended waiting period is mandated by rules or laws in many jurisdictions. Other police departments have agreements with police unions to honor the waiting period. This waiting period is recommended by Bill Lewinski, a behavioral scientist who many police officers believe to be the definitive expert on interviewing officers after shooting. Lewinski is a professor emeritus of Law Enforcement at Minnesota State University and the founder and director of the Force Science Institute, a research, consulting, and training organization focused on human behavior in use-of-force situations.

Lewinski has studied police use-of-force issues since 1975 and has opined that “delay enhances an officer’s ability to more accurately and completely respond to questions.” Lewinski has recommended “a recovery period of at least 48 hours before being interviewed in depth.”

Of course, if delay after a stressful event enhances memory, one might expect the police to delay interrogations of the people they arrest for shootings for 48 hours to give their memories a chance to improve. That isn’t their practice, because the real benefit of delay to a shooter is the opportunity to fabricate a coherent and innocent explanation of the shooting.

New Study by Criminologists

Criminologists Geoff Alpert, Louise Porter, and Justin Ready conducted a study to test the theory that a police officer’s memory will benefit for a cooling-off period. The study involved 87 police officers who participated in a live active-shooter simulation in an abandoned building. The officers were divided into two groups: half were interviewed immediately after the shooting and the other half was interviewed two days later. The first group was also interviewed two days later, to see how their memory performed in a second interview.

The interview process consisted of 19-multiple choice questions related to the shooting. Nine questions were related to the threat and 10 questions were about nonthreatening details. Following the interviews, the researchers concluded that the officers’ cognition “did not seem to be directly affected by how recently they had experienced the scenario, and no significant improvement was evident after two days either between or within groups.”  The researchers noted that the “recall of non-threat related information was significantly better in the immediate condition compared with the delayed condition.”

The researchers concluded that early questioning can aid memory retention. They stated, “We did not find any evidence … that delay improves either recall or cognitive capability that could indicate enhanced ability to respond to questioning.”

Lewiniski criticized the study and its use of multiple-choice questions to evaluate accuracy of memory and stress levels. Lewinski suggested that a more realistic study would involve heart rate and pulse monitors and trained cognitive interviewers. Lewinski also noted that the study did not take into account that many officers have worked long hours before the time of a shooting or post-event interview, which harms cognitive abilities. Notably, Lewinski has not conducted the “improved” studies to determine whether the results would support his theory that delayed interrogation following a stressful event improves memory.