Study: Don’t wait to question officers in shootings

In the hours after a police officer shoots someone, here’s something investigators usually don’t do: Interview the officer.

For years, the accepted wisdom in the police community has been that the officer should be given time to calm down from the traumatic event and that full sleep cycles once or twice before an interview will enhance his or her recall of the episode. Some jurisdictions have rules or laws mandating a waiting period, and some departments have reached similar agreements with police unions.

“Officers should have some recovery time before providing a full formal statement,” the International Association of Chiefs of Police states in its “Officer-Involved Shooting Guidelines.” The guidelines say, “An officer’s memory will often benefit from at least one sleep cycle prior to being interviewed leading to more coherent and accurate statements.”

But a new study of 87 veteran police officers, some interviewed immediately after active-shooter training and some two days after the training, could start to change that thinking. “We did not find any evidence,” wrote criminologists Geoff Alpert, Louise Porter and Justin Ready, “that delay improves either recall or cognitive capability that could indicate enhanced ability to respond to questioning.”

Even though officers who were questioned shortly after emerging from a high-stress scenario “felt heightened anxiety, and reported less confidence in their cognitive ability,” the study found that those factors “did not seem to impede officers’ ability to recognize details of the scenario, or form new memories and perform in the cognitive tasks.”

The study added a touch of common sense, noting, “While our results suggest immediate questioning is better for memory, this must be considered alongside other priorities, such as protecting and optimizing officer well-being,” a component recommended in every police shooting case.

The study also built on a commonly held perception about memory. “One of the most fundamental laws of memory,” said Stanford professor Elizabeth Loftus, a renowned expert on human memory, “is that it fades over time.” She noted that memory “not only fades, but is also vulnerable to post-event contamination, or eroding.” Loftus said that “we couldn’t see any good reason for this kind of long delay” in conducting police interviews.

Bill Lewinski of the Force Science Institute is regarded by many police officials as the definitive expert on the subject of interviewing officers after shootings. He is a behavioral scientist who has studied police use-offorce issues since 1975. “Delay enhances an officer’s ability to more accurately and completely respond to questions,” he wrote in one widely cited paper, arguing for “a recovery period of at least 48 hours before being interviewed in depth.”

He was critical of the Alpert group’s paper, which was first previewed at a national police chiefs’ conference and is being reviewed for publication. Lewinski said there were “serious flaws in the current research. The best study has not been done.”