ABSTRACT
Madden ... The second was the doctor’s opinion from what he observed by his examination of Madden of what Madden’s normal behaviour might be like; in other words, as counsel put it, was he more prone to hysteria than a normal person, according to the doctor’s observation?’ The Court of Criminal Appeal came to the conclusion that the evidence was properly excluded on the principle set out in Gunewardene’s case. On the same ground, they also rejected an application to tender additional evidence which was not available at the trials as to the medical condition of Madden, as shown by matters which occurred after the alleged crime. Within two months of it Madden had pleaded guilty to loitering with intent. He was then certified as being subnormal, and an order was made under the Mental Health Act 1959 for his detention in a hospital. The reports since his admission showed him to be an hysterical, fanciful and untrustworthy person. The Court of Criminal Appeal certified that a point of law of general public importance was involved, namely: ‘Whether, having regard to Rex v Gunewardene or otherwise, counsel for the defence ought to have been permitted to put to a medical witness called on behalf of the accused a question designed to obtain an expression of the witness’s opinions on a matter relating to the general mental condition of the witness who had given evidence for the prosecution, namely whether he was normally of an unstable or hysterical disposition.’ ... The second question, whether it was permissible to impeach the credibility of
Madden, qua witness, by medical evidence of his hysterical and unstable nature, raises a wider and more important problem which applies to evidence in criminal and civil cases alike ... Human evidence shares the frailties of those who give it. It is subject to many crosscurrents such as partiality, prejudice, self-interest and, above all, imagination and inaccuracy. Those are matters with which the jury, helped by cross-examination and common sense, must do their best. But when a witness through physical (in which I include mental) disease or abnormality is not capable of giving a true or reliable account to the jury, it must surely be allowable for medical science to reveal this vital hidden fact to them. If a witness purported to give evidence of something which he believed that he had seen at a distance of 50 yards, it must surely be possible to call the evidence of an oculist to the effect that the witness could not possibly see anything at a greater distance than 20 yards, or the evidence of a surgeon who had removed a cataract from which the witness was suffering at the material time and which would have prevented him from seeing what he thought he saw. So, too, must it be allowable to call medical evidence of mental illness which makes a witness incapable of giving reliable evidence, whether through the existence of delusions or otherwise. It is obviously in the interest of justice that such evidence should be available ... Medical evidence is admissible to show that a witness suffers from some disease or defect or abnormality of mind that affects the reliability of his evidence. Such evidence is not confined to a general opinion of the unreliability of the witness but may give all the matters necessary to show, not only the foundation of and reasons for the diagnosis, but also the extent to which the credibility of the witness is affected. I would therefore allow the appeal.25
