How reliable is Witness Testimony? Part 4 of 7 of the ‘What is Investigative Psychology?’ series

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Eyewitness testimony is the evidence that you get from someone who has witnessed a crime. Instinctively, people tend to believe and rely on it to a great extent. It can be seen as a factor that

can sway a judge and/or jury to establish the guilt or innocence of a defendant (Loftus, E.F. (1979), Eyewitness Testimony. Cambridge, MA: Harvard University Press). It is often used in the initial

stages of an investigation, for example when a witness reports the perpetrator was of a certain appearance, then the police will be looking for potential suspects who match that description.

Witnesses’ evidence is also used in court when either the prosecution or defence try to convince the jury that a certain person is or is not guilty. However, whilst in the past, the criminal justice process has relied greatly on eye witness accounts and still does, over the past few decades we have learned more and more about how unreliable this kind of evidence can be. It took DNA

evidence to exonerate a number of innocent people who had been convicted based on eyewitness evidence (Wells, G.L. & Olson, E.A. (2003) Eye Witness Testimony, Annual Review of Psychology,

Vol. 54: 277 – 295) And mistakes made unwittingly by eye witnesses are a substantial cause of wrongful convictions (Scheck, B., Neufeld, P. & Dwyer, J. (2000) Actual Innocence: Five Days to

Execution and other Dispatches from the Wrongly Convicted, Bantam Doubleday Dell Publishing Group).....