Identification evidence can be powerful inside the courtroom, but many studies have found that eyewitnesses often have a genuine, yet mistaken, belief that they have identified the person responsible for a crime – their “recollection” being affected external factors.
In one study, a startling 63% of those surveyed believed that “human memory works like a video camera, accurately recording the events we see and hear so that we can review and inspect them later.”
By contrast, all 16 experts surveyed disagreed with that statement – finding that human memory is often reconstructed, and can be influenced by many factors including the manner of police questioning.
The public’s confidence in identification evidence can be particularly dangerous when it comes to criminal trials, potentially leading to wrongful convictions.
Post Identification Feedback
The term ‘post identification feedback’ refers to external factors which can affect whether an identification is made, or not made for that matter.
Leading police questions which suggest a particular suspect’s guilt, the tone of voice used, or even non-verbal cues such as body language and the positioning of photographs can affect whether an identification is made.
Research on memory reconstruction also looks at how a person’s tentative identification – eg “I think it was him” – can later change into positive affirmation eg “I’m positive that’s the man” due to post identification feedback.
According to the research, such changes are extremely common – one 2011 study looked into the trial transcripts of 161 people who were convicted of crimes but later exonerated by DNA evidence. In 57% of those cases, the eyewitness had not been certain of identity at the time of the initial identification, but later testified they were positive.
‘Confidence malleability’ refers to the tendency of an eyewitness to become more or less confident in their identification due to post-identification feedback.
The original experiments demonstrating this effect, by Wells & Bradfield (1998), had participants identify a person from a culprit-absent lineup; where all identifications were mistaken.
The participants were then randomly assigned to receive confirming feedback (“Good, you identified the suspect”), disconfirming feedback (“Actually, the suspect was Number x), or no feedback at all.
The study found that those who received confirming feedback inflated their recollections of certainty, while those who received disconfirming feedback did the opposite.
In the control condition, 15% of (mistaken) eyewitnesses said they were “positive” they identified the actual gunman, while a whopping 50% of those who received confirming feedback did the same.
There are many examples of misidentification leading to conviction.
In one American case, the victim Jennifer Thompson was initially hesitant when she mistakenly identified Ronald Cotton as the man who sexually assaulted her at a college campus.
But after police said, “We thought that was the guy”, she described relief that she had “gotten it right.”
On the strength of her mistaken identification, Mr Cotton was convicted and spent 11 years in prison until DNA evidence revealed that another man, Bobby Poole, was actually responsible.
Link Between Witness Confidence and Accuracy
Public perception about the link between the confidence of a witness and the reliability of their evidence is also at odds with the findings of experts
While 37.1% of potential jurors in one study agreed with the statement, “the testimony of one confident eyewitness should be enough evidence to convict a defendant of a crime,” all 16 experts disagreed.
In fact, researchers found that eyewitness confidence tends to only modestly relate to identification accuracy. In other words, it doesn’t follow from the fact that a witness is supremely confident in their identification, that their identification is far more likely to be accurate.
The public perception of a confident witness can lead to disastrous consequences – with the US Innocence Project already leading to the exoneration of well-over 300 innocent people, 18 of whom had been sentenced to death, and most of whom were wrongly identified and released from prison when DNA testing found they could not have committed the crime.