Sorry, Mr. Bratton. Science says no.
The scenario is all too familiar. A police officer with a dash-cam or body camera stops an individual, the situation escalates, the individual is apprehended, a charge is made and the individual is arrested. The question is whether prior to being questioned or even prior to writing a report, should the officer be permitted to view the recorded footage?
Philip Eure, the Department of Investigation’s Inspector General for the NYPD, recently recommended that police officers be prevented from viewing recorded footage before giving a statement to investigators. Quick to respond, New York’s City Police Commissioner, Bill Bratton called this “one of the recommendations of the I.G. that we strongly, strongly disagree with and will not support under any circumstance.” His concern was enhancing the integrity of police officers; “I am not intending to use the cameras to play a game of gotcha with the cops.”
This is a complex issue, but one for which cognitive science research provides a clear answer. If the purpose of any investigation is to get the most complete, accurate information possible, then it could be argued that the officer should view the footage, probably multiple times, prior to being questioned and prior to testifying. Human memory is notoriously flawed, but we can consider recorded footage to be “ground truth.” So according to this argument, bolstering the officer’s account by having him view the recorded footage effectively serves to enhance the accuracy of the officer’s report. And it does.
The problem is that in so doing, two independent lines of evidence – the officer’s eyewitness memory and the recorded footage – are no longer two independent lines of evidence. That is, the eyewitness memory of the officer has been tainted by viewing the recorded footage. If in the prosecution of the case the officer is to serve as an eyewitness, and his memory is to be preserved untainted, then it is critical that the officer not view the footage.