Forensic Psychology For Dummies (26 page)

In some US states, notably Oregon, a need exists to determine whether a person has the mental competence to request assistance in hastening their own death. Increasingly, psychologists are active in providing guidance to such proceedings and so in this section I mention some of the issues that distinguish this sort of expert evidence.

One crucial point is that, whereas in most criminal cases the defendant has to be found guilty
beyond all reasonable doubt
, in civil proceedings the burden of proof is much weaker, often phrased as
on the balance of probabilities
. Therefore, a much wider range of expertise is allowed into these legal deliberations.

Another important aspect of non-criminal proceedings is that the people to whom the psychologist’s evidence relates are likely to be rather different from the run-of the-mill criminals seen in most criminal courts. Youngsters, or
juveniles
as they’re known in legal parlance, are often dealt with in a much more informal context, as are children who are at the heart of child-custody hearings. The psychologist therefore has to guide the court on such sensitive and complex matters as relationships between parents and children, or how amenable a youngster is to rehabilitation.

These varied forms of consultation to civil courts make special demands on forensic psychologists that aren’t nearly so apparent in criminal proceedings:

Care must be taken in how an individual is labelled, because this can become part of their file and can shape their life as well as how the justice system deals with them. Labelling someone with conditions such as autism and Asperger’s syndrome (I consider the assessment of young offenders in Chapter 9), for instance, can give all the wrong signals and blight what a person can do for many years to come.

The expert has to be willing and knowledgeable not only about the problem a person has that led them to the court, but also what can be done about it. Informing those present of the approaches and ‘treatments’ available can be more important than assigning any diagnostic label.

Relationships between people, such as children and their parents or youngsters and their lawyers, are often an important part of the psychologist’s assessment. This is much more difficult to evaluate than the mental state of an individual. It requires skills in relating to people and enabling them to be honest with you that aren’t so crucial in many criminal cases.

Often much more heated emotion is associated with the proceedings, especially in child-custody litigation. The psychologist may be very vulnerable to challenges about his ethics or expertise arising from the intense passions involved.

Keeping Your Lips Sealed: What an Expert Can’t Comment On

As I explain in the preceding sections (possibly at more length than you expect!), much legal debate exists about who’s an expert and what can be allowed as expert evidence. Of course, the expertise must be relevant to the case in question, but additional constraints surround this issue that you need to understand if you’re to appreciate how some psychological expertise gets into court and some doesn’t.

Staying within your competence

Although some people may like to present themselves as all-knowing authorities on many things (you see them on TV often enough!), professional humility is crucial for a forensic psychology expert witness to be effective in court and avoid committing perjury or even contempt of court. Experts have to stay within their area of expertise.

This fact may seem obvious, but remember that the person deciding who a court accepts as an expert (and what that expertise is to cover) isn’t a professional in the area in question but in the law, that is, a judge or magistrate. The court therefore often relies on experts themselves to indicate when they’re being asked to comment on something outside their competence.

For example, an expert on the use of language (who I mention in Chapter 5) was asked to offer an opinion on the probability of a particular form of words being used. But although the expert knew about language, he didn’t know much about statistics and how to calculate probabilities.