Forensic Psychology For Dummies (25 page)
Read Forensic Psychology For Dummies Online
Authors: David Canter
In some countries the requirement for being an expert for the court is much stricter. In France, for instance, experts are usually on a registered list.
But how is new expertise that comes along to be evaluated, such as the ‘lie detector polygraph’ in the Frye case in 1923? Well, the judge in that case was clear about the need to determine the soundness of the expertise. He said:
Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs.
In other words, no new-fangled idea is to be allowed as evidence just because someone claims it works. Only when the scientific community, from which that sort of evidence comes, generally accepts what’s being claimed does the court allow it. The polygraph has never reached that acceptable standard and so has never been allowed in court.
This ‘Frye Standard’ still holds in some US states, but overall it was regarded as too restrictive, and so a different standard for judging whether expert evidence was acceptable was introduced following the case of
Daubert versus Merrill Dow Pharmaceuticals Inc.
In 1993, Jason Daubert claimed that the birth defects he was born with had been caused by the chemical Bendictin sold by Merell Dow. He brought evidence from laboratory and animal studies to support his claim. His evidence was challenged as not being generally accepted by the relevant scientific community, but in the course of a complicated legal process the US Supreme Court determined that the original Frye Standard was no longer the law and that the crucial issue was:
If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education, may testify thereto in the form of an opinion or otherwise.
This statement changed the rules and led to Daubert’s evidence being admissible. Now what mattered was whether the person giving evidence was expert enough, not the general acceptance in the scientific community of the procedure being drawn on. In the curious way of the law, the effect was to make the judge the person who decides on whether evidence is sound enough to be acceptable instead of the scientific community from which the expert comes.
The Daubert ruling seems less stringent than the Frye Standard, and you’d expect courts to be more open to developments in science that aren’t yet established enough to gain general acceptance by the scientific community. In many court cases, the judge reviews the proposed expert evidence and decides whether or not to admit it. Instead of opening the floodgates to all sorts of novel scientific discoveries, however, the indications are that judges have become more conservative since Daubert. Few judges want to be the first to allow a new form of evidence that may later be shown to be rubbish! But some do, which is why expertise may be accepted in some courts but not in others.
UK approaches
In contrast to the US system of an overarching set of guidelines, the UK courts rely much more on what happened in previous cases, often known as
precedent
(although of course ‘rules of evidence’ and other frameworks can be drawn on). In general, UK courts are much more cautious about what’s allowed as expert evidence than in the US, which is why many forms of evidence (notably the syndrome evidence I discuss in Chapter 11) is much more likely to emerge in a US court first, long before it sees the light of day in the UK.
In Britain, a judge determines whether any expert is allowed to give evidence, and draws on his own understanding of the expertise involved. As far as psychology is concerned, this tends towards acceptance of views that appear to have strong medical roots. So a psychiatrist claiming that psychopathy (which I examine in Chapter 10) is a medical condition over which the defendant has no control, and therefore the person needs to be regarded as a patient rather than a criminal, probably gets a hearing from the judge. A psychologist proposing that a person can plan suicide without indicating this intention to anyone is far less likely to be listened to as there is no medical basis to the opinion.
Appearing as an expert in civil proceedings
Many courts don’t operate in as formal a way as criminal courts and other legal settings that deal with crimes from burglary to murder. Civil courts often operate as if they’re informal courts, and they’re not bound by the same legal constraints. They can deal with a great mix of matters, including the following cases:
Child custody
