Networked Knowledge – Media Report

[This edited version of the newsletter has been prepared by Dr Robert N Moles]

South Australia homepage
Article: Australian law on miscarriages of justice
Article: UK law on miscarriages of justice
Article: USA law on miscarriages of justice

[This article was scanned from the Proceedings of the Australian Forensic Science Society, Volume 4, Number 1, April 1986, pp8-11.]

NATURE & NEEDS OF FORENSIC SCIENCE

as reported by Rupert Best in Search Vol 16 No 3-4 (1985)

The general public seems to be unclear about the methods, objectives and importance of scientific investigation of evidence found at the scene of crimes, said Dr Roy Scragg, Chairman of the South Australian Division of ANZAAS, opening a recent Public Awareness Forum on ‘Forensic Science and You’ held by the Division at the State Convention Centre. The Forum tried to define the requirements for a forensic science service that would be acceptable both to scientists and to responsible lawyers. During the discussion period Dr WJ Tilstone, the newly appointed Director of the Forensic Science Division, SA Department of Services and Supply, undertook that ‘the doors of Divett Place will be open equally to the Defence and the Prosecution’.

In the first paper the State Coroner, Mr KB Ahern, sketched the advances made over the years in the knowledge, technology and methodology of forensic science. He regretted the current decline in public confidence in the evidence of forensic science (for which he blamed both lawyers and scientists) and suggested ways for correcting it.

The work of analysis carried out in a laboratory, the identifications and exclusions made at the scene of the crime, the deductions drawn from experiments and the examination of material, all have to be reduced to facts which are in the end put to witnesses by lawyers and then adjudicated upon by lawyers, or by a body of laymen under the direction of a judge. So the forensic scientist is placed in a peculiarly dependent position with regard to the lawyer, and similarly, the lawyer is placed in a vulnerable position with regard to the scientists; and since the technical aspects of forensic science need to be understood by lawyers and jurors it is important to reduce expert evidence to simple language which people of average intelligence can understand.

Mr Ahern deplored cross-examinations ‘by an aggressive, abusive, and sometimes ignorant counsel’, which sometimes happened, and advocated training potential scientific witnesses in the skills and techniques of giving evidence in court. He rejected claims that our system of justice in the criminal sphere ‘is suspect’, considering it ‘one of the fairest, and safest systems of justice in the world, having regard in particular to safeguards accorded to persons charged with crime: I have no doubt that due to these safeguards many guilty people have been acquitted.’

Dr Tilstone said that, in the Adelaide Forensic Science Centre, all tests would be carried out by competent scientists, and would be repeated by a second scientist whenever possible.

Evidence derived from forensic science can be used by the court in one of three ways, said Dr Tilstone:

(a) The evidence may indicate that a particular offence has been committed
- for example, identifying a fire as arson rather than accidental.

(b) The evidence may eliminate a suspect - for example, finger-printing or blood grouping.

(c) The evidence may corroborate other evidence - for example, fibre traces and paint or glass fragments.

The first two types of evidence will usually be definitive and will be of value to police officers in the course of their investigations. Most forensic science evidence can cross the boundaries between the three types of evidence; thus, if blood grouping fails to eliminate a suspect, it will become corroborative evidence.

A forensic pathologist, Dr Ross James, explained the role of his profession - ‘the study of injury and disease and its application to the law’. There is a general shortage of forensic pathologists, he said: only two full-time pathologists are available in South Australia. Doctors are reluctant to give up their clinical duties and are not attracted by the problems of our adversary legal system.

The post-mortem examination is simply an extended clinical examination. Approximately 2,000 coronial post-mortems are carried out in South Australia each year. The cause of death, though of interest to the Registrar of Births and Deaths, and sometimes of great interest to the media, is of secondary importance. The main aim is to determine the manner of death - natural or unnatural, and if unnatural, whether murder, suicide or accident.

In the investigation of homicide cases the post-mortem itself is frequently of little probative value. It is the examination of trace evidence on or within the body by forensic scientists that can point to the particular offender. At all times during work on suspicious death cases, co-operation between the State Coroner, the investigating police and the forensic scientists is essential: The transfer of information and results is necessary to assist the investigating police in not making needless arrests.

Because our criminal justice system is adversarial, any witness must appear for one side or the other. Nevertheless, specialist scientists should attempt to behave as court witnesses. It is also desirable that such witnesses should remain detached from the results of trials, since verdicts are reached for many reasons other than the evidence of an individual witness, Dr James pointed out.

Detective Superintendent P. A. Collins spoke on the role of the police, and in particular the scientific section. He quoted the Curry Report to the South Austra1ian Government on the Forensic Science Services. Dr A. S. Curry, former Director of the Home Office Laboratories, had categorised the foundation of a Forensic Science Service as follows:

to find more information from material left at the scene of a crime that will lead the police to a particular subject - i.e. first find the criminal;

to increase the specificity of analytical methods so that material from a suspect can be more closely related to that from a scene of a crime - i.e. get good evidence;

to work not only accurately but quickly. (Forensic scientists are only too aware of police problems associated with delays in forensic analysis.)

‘The Role of a Specialist Consultant’ was the title of a paper presented by Beryl Morris, Forensic Entomologist of the South Australian Museum. Her concern, she said, was ‘with the insects which feed on the decaying flesh of corpses. If we can tell how old an insect found on a body is, and what attracts that species to a body, we can sometimes estimate the time that has elapsed since death... If more than about a day has elapsed since death, traditional methods of forensic medicine become less accurate in determining a time of death, making it necessary to seek alternative methods. The age of insects on the body is one such alternative.

Miss Morris went on to deal with the effect of various environmental and other forces on the behaviour of various insects. Her paper was well illustrated by diagrams on an expertly used overhead projector. If her contribution is an example of how she would present evidence to a jury, then I would say that the jury would have no cause whatsoever to say that they had not understood.

In fact, the papers of Miss Morris, Dr Tilstone and Dr James were outstanding in relation to length, clarity, interest, and manner of presentation. All three are scientists, and their papers gave the lie to criticism by the media of the ability of scientists to make things simple and understandable to the non-specialist. They deserve to be printed in full somewhere, illustrations and all.

Dr WB Taylor’s paper on ‘the role of statistics in determining the value of evidence’ dealt with a difficult subject in an interesting, simplified manner. The meaning of statistical data, he emphasised, depends on:

(a) the type and nature of the people who collected them - who chose those particular measurements - and

(b) the type and nature of the people called on to interpret them;

‘so that statistics and their meaning are reduced to people and their judgments’. The validity and usefulness of information would depend on, for example:

(a) why these particular measurements ware taken in preference to other data or evidence;

(b) whether the statistics represent a full statement of the investigation (i.e. are those tests where dissimilarities were observed also included?);

(c) the care taken to avoid any possible bias;

(d) the time-span over which the statistical evidence is of value;

(e) the destructiveness or otherwise of the tests used.

Finally, scientists and statisticians take pride in their respective disciplines, and those involved in the process of law are no exception. But it should always be remembered that judgements in legal cases are ultimately decided by the legal process, its rules and principles, and that what may be regarded as satisfactory in law may not be so regarded in science. Where the disciplines of science and the law at some stage interact, it is of much importance that at the interface the exchange of information must proceed in a manner in no way detrimental to the integrity of either.

In the last paper, Mrs ME Shaw, a barrister who has appeared for the defence cases in murder trials, set out the following ‘tests that a legal practitioner can apply’ to the evidence as presented:

(a) Is the particular scientist sufficiently qualified to perform the test that was carried out?

(b) Has the scientist chosen a method of testing that is capable of giving any meaningful result?

(c) Has the scientist correctly interpreted the results?

(d) What are the limitations of any opinion that is expressed?

(e) If an expression of opinion is given that materials found at a crime scene and on the suspect are similar, what is the significance of that claimed match in terms of the case against an accused person?

(f) Is the scientist expressing an opinion in an area which is outside his field of expertise?

Unfortunately, Mrs Shaw spent most of her time applying these questions to murder trials that had taken place in the fairly recent past and from which such authorities as the Government of South Australia had already learned, and instituted reforms.

The forum was intended to define the requirements for a forensic science service that would be acceptable to established scientists and responsible lawyers - to look ahead and plan accordingly. It became clear that the scientists on the panel were, in fact, conforming to the requirements and criteria advocated by all the speakers. If Dr Tilstone’ s plans could be fully implemented, especially by appointing adequate staff of the right quality (as is planned for South Australia), and these plans are extended to all the states, the main problems would be solved. It would then remain for the legal profession to put its house in order and ensure an end to the calling of so-called scientists of questionable credentials in the hope of destroying or reducing the credibility, in the eyes of the jurors, of responsible and fully qualified scientists of an independent forensic science service.

RUPERT BEST

Top of Page