New measures for witnesses: are they performing as anticipated?
PhD thesis, University of Glasgow.
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The route of the witness through the criminal justice system, from identification to testimony, has always been fraught with difficulty. There are innumerable sources of influence, intimidation and manipulation which can affect a witness’s performance at any point on this pathway. In recent years, and in an effort to resolve several of the issues surrounding witness performance, the British Government have introduced a number of legislative measures to improve performance at identity parades and enhance the court experience of vulnerable witnesses and thereby improve the quality of their testimony. While it seems that these measures have been generally well received, there remain some valid questions over their implementation and whether they are eliciting the desired effects.
The sequential identity parade system, V.I.P.E.R. was devised primarily as a cost-cutting procedural change by West Yorkshire Police in 1999. However, V.I.P.E.R.’s design was heavily influenced by the large extant literature declaring a sequential superiority effect for target absent parades. Specifically, the data claim that sequential identity parades significantly reduce the rate of false identifications from target absent parades whilst preserving hit rates for target present parades. Yet all of the studies purporting this effect have used a very different procedure to that employed by V.I.P.E.R.; these studies use, and recommend, a strict sequential procedure whilst UK legislation requires V.I.P.E.R. parades to be shown twice. Thus the effects of using a V.I.P.E.R. parade upon rates of identification and misidentifications have yet to be empirically investigated. The results of this study revealed that there was no significant effect of parade presentation mode upon rates of correct identifications for target present parades or the rate of mistaken identifications in target absent parades.
The next step for many witnesses is the progression of their case to trial. The incidence of intimidation and vulnerability of adult witnesses appears to be increasing and so a range of Special Measures, more commonly used with child witnesses, were extended to adult witnesses who meet legislative criteria. However, there again has been no investigation into the effects the use of the Special Measures for adult witnesses has upon jurors ‘perceptions of that witness, the defendant and, if there is a change in perceptions, whether they are substantive enough to alter the trial verdict. The current experiments revealed that the use of a screen does not significantly alter jurors’ perceptions and had no effect on conviction rates. The use of live CCTV links led the witness to be perceived as less credible but again this did not affect the verdict. It is the use of pre-recorded video evidence which raises the most concern; witnesses testifying in this manner are perceived as significantly less credible and believable which in turn has a significant effect upon conviction rates. However, when tested in a deliberating jury group situation, all the Special Measures were associated with the witness being perceived as more credible compared to the control condition, although these differences were not significant, and there was no significant effect upon the rate of guilty verdicts across all conditions.
Overall, it appears that the implementation of both of these legislative steps have had varying degrees of success. While the V.I.P.E.R. identity parade procedure has reduced running costs it appears that there are no significant differences between V.I.P.E.R. and simultaneous procedures for either target present or target absent identity parades. Conversely, it appears that the introduction of the Special Measures for vulnerable adult witnesses has been largely well received and tentatively successful in reducing witness anxiety. The data suggest that there are no significant negative effects associated with using these Special Measures, certainly under the more ecologically valid condition of the deliberating jury group. Nevertheless, a series of policy recommendations have been made for both identity parade and testimony procedures with the aim of further enhancing the witness’s performance and experience through the criminal justice system.
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