Facial composites, or photofits as they’re commonly known, are sometimes used by the police to get a visual impression of a suspect in serious crimes. These facial composites are put together from an eyewitness’s memory soon after the crime, and may then form part of the evidence in a trial.

In this study, a team at Arizona State University examined what effect good and poor matches between a facial composite of a ‘suspect’ and a photo of a ‘defendant’ had on ‘jurors’ in a mock trial.

It was found that a good match between suspect composite and defendant photo led jurors to believe that the defendant was guilty, as you might expect. A good match also made jurors think that the eye witness had got a good look at the culprit and that she was accurate.

However, a poor match between suspect composite and defendant photo did not lead jurors to disbelieve the eye witness, nor believe the defendant any more innocent than if they had seen no prior composite at all.

Lead researcher, Dawn McQuiston-Surrett, said: 'We expected a poor match between facial composite and defendant photo to lead jurors to question the eye witness’s credibility - as they have clearly made errors at some stage. You might expect jurors to question the defendant’s guilt as a result.

'However, jurors shown a poor match rated the eye witness’s accuracy, quality of view, strength of witness testimony, strength of defence case and defendant guilt similarly to in a test condition where they saw no facial composite. Our study found that a poor match was not enough to impact on jurors judgements at all.'

'This was surprising, so we then asked the mock jurors to rate how difficult they believed producing a facial composite would be,' continued Dawn McQuiston-Surrett. 'Many thought it would be difficult to do, so it could be that jurors are unwilling to penalize the prosecution based on facial composite evidence because they feel that creating these facial composites is a difficult task.'




Source: British Psychological Society (Press Release)

References

Loftus, E.F. (1974). Reconstructing memory: The incredible witness. Psychology Today, 8, 116-119.

McQuiston-Surrett D.E. (2008). Evaluation of facial composite evidence depends on the presence of other case factors. Legal and Criminological Psychology Volume 13 Part 2 September 2008