Joint Institute of Applied Ethics and
Experts and Institutions
Seminar
Wednesday 26 January 2011 2.15 pm
Room no BJ-TR2
Brynmor Jones Library
Andrew Roberts
Associate Professor, Law School
University of Warwick
Expert Evidence on the Reliability
of Eyewitness Identification: A Non-Epistemic
Rationale
Reliance on eyewitness identification evidence
in criminal trials is both commonplace and problematic. There
have been persistent calls for the courts to make greater use of
the accumulated findings of relevant psychological research by
permitting experts to address juries on the frailties of the
cognitive processes that precede a witness's claim that the suspect
is the culprit. Those who advocate the reception of expert evidence
usually claim that without expert testimony fact-finders are unable
to satisfactorily distinguish eyewitness identification evidence
that is reliable from that which is not; that fact-finders tend to
place too much weight on this kind of evidence; and that expert
evidence will suppress this tendency.
In this paper Professor Roberts argues that expert evidence based
on the generalisations that are used to describe the findings of
experimental psychological research is not particularly helpful to
a tribunal of fact; that it reveals nothing about the accuracy of
the identification made by the testifying witness, and; that if the
expert evidence is accepted it can do no more than make the jury
sceptical of that witness’s testimony. He does not claim, however,
that there should be a prohibition on the reception of expert
evidence concerning the reliability eyewitness identification
evidence. It should be admissible as a means of redressing the
unfairness suffered by the accused where the state fails to fulfil
its obligation to do all that can reasonably be expected of it to
avoid convicting innocent defendants. He will suggest that expert
testimony is justified (i) where the state has failed to prescribe
pre-trial procedures that are likely to produce the most accurate
outcomes, and (ii) if such prescription exists, where the state's
agents have failed to adhere to the prescribed
procedures.