That eyewitnesses make errors – errors of a catastrophic nature that can send an innocent person to jail for decades or even face a sentence of death – cannot be doubted.  As confirmed by the INNOCENCE PROJECT, “[e]yewitness misidentification is the greatest contributing factor to wrongful convictions proven by DNA testing, playing a role in more than 70% of convictions overturned through DNA testing nationwide.”   http://www.innocenceproject.org/causes/eyewitness-misidentification/ (last visited September 30, 2016).

               But are the lessons from these exonerations of more general applicability; of use in civil as well as in criminal cases?  The simple answer is “certainly.”

The single most important lesson for anyone preparing to interview a fact witness is that the mind is not a video recorder that captures events and information; maintains that information without modification; and then recalls it accurately.   To the contrary, “[m]emory is much more than a simple retrieval system…Rather, the nature of memory is constructive and influenced by a person’s current state as well as intervening emotions, beliefs, events and other factors since a recalled event.” http://historynewsnetwork.org/article/152111#sthash.CtsVIakR.dpuf (last visited September 30, 2016).

Memory scientists teach that this is a three-stage process – encoding, the time of initial input of information; storage, the time during which the memory is retained; and retrieval, the telling/interview/interrogation process.  At each stage errors may occur.

At encoding, the witness may get only a partial view or actually ‘see’ an incorrect detail.  This is best shown by an experiment conducted more than 100 years ago by the great researcher Hugo Munsterberg:

[There was] a meeting of a scientific association, made up of jurists, psychologists, and physicians… Suddenly, in the midst of the scholarly meeting, the doors open, a clown in highly coloured costume rushes in in mad excitement, and a negro with a revolver in hand follows him. In the middle of the hall first the one, then the other, shouts wild phrases; then the one falls to the ground, the other jumps on him; then a shot, and suddenly both are out of the room. The whole affair took less than twenty seconds. All were completely taken by surprise…It seemed most natural that the President should beg the members to write down individually an exact report, inasmuch as he felt sure that the matter would come before the courts.

Of the forty reports handed in, there was only one whose omissions were calculated as amounting to less than twenty per cent of the characteristic acts; fourteen had twenty to forty per cent of the facts omitted; twelve omitted forty to fifty per cent., and thirteen still more than fifty per cent. But besides the omissions there were only six among the forty which did not contain positively wrong statements; in twenty-four papers up to ten per cent, of the statements were free inventions, and in ten answers — that is, in one-fourth of the papers, — more than ten per cent of the statements were absolutely false, in spite of the fact that they all came from scientifically trained observers. Only four persons, for instance, among forty noticed that the negro had nothing on his head; the others gave him a derby, or a high hat, and so on. In addition to this, a red suit, a brown one, a striped one, a coffee-coloured jacket, shirt sleeves, and similar costumes were invented for him. He wore in reality white trousers and a black jacket with a large red necktie.

http://psychclassics.yorku.ca/Munster/Witness/memory.htm (last visited September 30, 2016).  If you need more convincing, take the “selective attention” test at https://www.youtube.com/watch?v=vJG698U2Mvo .

The potential for change in memory continues.  During retention, the memory may fragment or be changed by new information, a process that may recur during retrieval.  Here, the most compelling illustration comes from an experiment by Elizabeth Loftus.  Subjects were shown a video of a car accident, and then asked to estimate the speed of the vehicles.  But rather than a neutral question of “what speed were the cars going at” the viewers were asked how fast the cars were going when they “contacted,” “hit,” “bumped,” “collided” or “smashed.”  The more intense the verb, the higher the speed estimate:



What came next was worse.  In a related experiment, witnesses were shown an accident video and again asked to estimate speeds using differing verbs to describe the contact.  One week later, those who viewed the video were asked whether there was any broken glass [when in fact there was none].  The more intense the verb, the greater number who ‘remembered’ broken glass.


http://www.simplypsychology.org/loftus-palmer.html (last visited September 30, 2016).  The questions as worded changed or ‘grew’ the memories.

One last lesson from the eyewitness cases bears study – the deleterious effect of time in eroding detail memory.  People remember the ‘gist’ of an event – being robbed or assaulted, or seeing a horrific crash – but the memory of details degrades rapidly, often within a day.  And degradation continues over time.  See, e.g. “Are Your 9/11 Memories Really Your Own?” http://blogs.scientificamerican.com/psysociety/are-your-911-memories-really-your-own/ (last visited September 30, 2016).

What are the lessons?  Interview as close to the event as possible and understand the limited reliability of interviews conducted far after the event; avoid words that may contaminate memory by suggesting an image or behavior; and learn and deploy alternative techniques such as cognitive interviewing.  This process has been described as deploying several techniques:

  • The interviewer tries to mentally reinstate the environmental and personal context of the crime for the witnesses, perhaps by asking them about their general activities and feelings on the day.  This could include sights, sounds, feelings and emotions, the weather etc.
  • Witnesses are asked to report the incident from different perspective, describing what they think other witnesses (or even the criminals themselves) might have seen.
  • Recounting the incident in a different narrative order.  Geiselman & Fisher proposed that due to the recency effect, people tend to recall more recent events more clearly than others. Witnesses should be encouraged to work backwards from the end to the beginning.
  • Witnesses are asked to report every detail, even if they think that detail is trivial. In this way, apparently unimportant detail might act as a trigger for key information about the event.

McLeod, “Cognitive Interview” (2010), http://www.simplypsychology.org/cognitive-interview.html (last visited September 30, 2016).

And the benefits of cognitive interviewing?  In one study, witnesses who viewed a video of a crime were interviewed 48 hours later.  Those who were the subject of cognitive interviewing remembered an average of 41.2 facts, while in a standard interview the number dropped to 29.4.  Id.