An interesting development in a Criminal Law case.

I thought I'd like to share this interesting piece of Law I came across recently during a trial, in which I was instructed by the Crown Prosecution Service in a Murder case to do an assessment of personality. It may be of interest to psychologists who get involved in criminal work.

Here's the scenario: First an expert (psychiatrist) produced a report for the defense, suggesting that the defendant did not have a personality disorder but did have "abnormal personality traits," (histronic) which he claimed could have influenced the defendant's decision making during the week of the alleged murder of his wife. The psychiatrist did not use any psychometrics.

In my report, I also suggest that there's not a personality disorder but agree there are some personality traits (though not histronic) but say it is unclear what relevance they have, if any. I based my conclusions on my review of the evidence, clinical interviews, STAXI-2, MCMI-III, PAI, WTAR and WASI.

At trial, the question that was raised was: should the jury judge even hear and consider the experts' evidence re personality traits if there is no disorder? A Voir Dire was held to consider this question. It was decided that they should not. This judgement was based on the following pieces of Law: R V Turner (1975): "where no mental abnormality is involved, such matters are within the 'common knowledge and experience' and can be understood by a jury. An Expert's opinion is only admissible to furnish the court with scientific information which is likely outside the experience and knowledge of judge/jury." This decision was upheld in Weightman (1991) and Cole (1995). That is, unless there's an Abnormality of Mind (which translates into a Mental Disorder), the jury can be confused by hearing scientific jargon that seeks to explain a defendants behaviour. They were considered to be perfectly capable of understanding that people with different personality styles will act differently and there can be more than one explanation for someone's behaviour under duress, without resorting to experts.

The judge pronounced the defense psychiatrist's evidence in this case "superfluous, and it trespasses upon matters which are within the jury's normal experience." Consequently, therefore, none of the expert psychiatric or psychological evidence was admissible and the general feeling was the defense psychiatrist should have just concluded No PD, full stop.

The outcome was that the defendant was found Guilty and given a 19 year sentence.

The barrister became aware of this piece of Law only at the very last moment (the night before we were due to testify). It has been very interesting to think how things might have progressed if the experts' testimony had been allowed. The whole area is a fascinating one: for example, in future, will there be less distinction made in Criminal law between Abnormality of Mind (i.e., when a serious disorder is present) and less serious mental/emotional conditions? Is it really within the jury's experience to understand how personality features (though not personality disorder) can account for inappropriate behaviour? Should there be different standards in Criminal v other proceedings? Don't we talk about significant personality feature and their impact on behaviour all the time in child & family work?

Please let us hear your thoughts on this?

Posted on Behalf of Dr Susan Jones by Gareth Nightingale