Interrogations-and-Confessions-Handbook

276 A Psychology of Interrogations and Confessions
2001, p. 439). This means that English law has a rather restrictive approach to
the admissibility of evidence from expert witnesses (Coleman & Mackey, 1995;
Fitzgerald, 1987; Gudjonsson, 1992c; Mackey & Coleman, 1991). Mackey and
Coleman (1991) argue that there are more problems with the admissibility of
psychological than psychiatric evidence, because the science of psychology focuses
more on normal behaviour; in contrast psychiatry is mainly devoted to
the diagnosis and treatment of mental disorder. Psychologists are not allowed
to give evidence on such matters as eyewitness testimony, unlike their counterparts
in America (Davies, 1983), although in practice there have been exceptions
to this rule (Gudjonsson & Haward, 1998). Generally, however, the evidence of
psychologists, like that of psychiatrists, has to deal with the presence of mental
abnormality. When this involves mental illness or learning disability the
evidence is readily admissible.
Problems can arise when dealing with diagnosis of ‘personality disorder’
rather than mental illness or learning disability. For example, in the case of
R. v. Mackinney and Pinfold ([1981], 72 Cr.App.R. 78) a social psychologist was
not allowed to testify as to the likely unreliability of the testimony of a ‘psychopathic’
prosecution ‘supergrass’ whom he had observed in court but never
formally interviewed. The decision to exclude the psychologist’s evidence was
upheld by the Court of Appeal. It was decided that
Whether or not a witness in a criminal trial is capable of giving reliable evidence
is a question of fact for the jury (Mitchell and Richardson, 1985, p. 420).
The principal set out in Turner has caused some difficulties. For example, in
R. v. Strudwick and Merry ([1994], 99 Cr.App.R. 326) it was decided that
The admissibility of expert psychiatric evidence is a question of fact in the particular
circumstances of the case. The law is in a state of development in this area.
There may well be mental conditions other than mental illness about which a jury
might require expert assistance in order to understand and evaluate their effect
on the issues of the case (p. 439).
The judgments in the Court of Appeal cases discussed in Part III illustrate
well how in recent years the law has changed in relation to the admissibility
of psychological and psychiatric evidence in the absence of mental illness. For
example, psychological and psychiatric evidence has been admitted in cases of
personality disorder, following the landmark case of Judith Ward ([1992], 96
Cr.App.R. 1; see Chapter 18 for a detailed discussion of the case and subsequent
legal developments). A formal diagnosis of personality disorder is not even
required for the admissibility of such evidence, as clearly ruled in R. v. O’Brien,
Hall and Sherewood (The Times, 16 February 2000):
. . . for expert evidence as to some abnormality to be admissible in respect of the
reliability of a defendant’s confession it is neither necessary nor sufficient that the
abnormality should fit into some recognised category; what is necessary is that
the disorder must be of a type which might render a confession or evidence unreliable
and it must represent a significant deviation from the norm (Richardson,
2001, p. 440; see Chapter 18 for details of the case and the ruling).