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Review Lecture: Forensic Science Author(s): A. S. Curry Source: Proceedings of the Royal Society of London. Series B, Biological Sciences, Vol. 199, No. 1135 (Nov. 14, 1977), pp. 189-198 Published by: The Royal Society Stable URL: http://www.jstor.org/stable/77255 . http://www.jstor.org/stable/77255 . Accessed: 20/05/2013 12:29 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at  . http://www.jstor.org/page/info/about/policies/terms.jsp

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Proc. R. Soc. Lond. B. 199, 189-198 (1977) Printed in Great Britain

REVIEW

LECTURE

Forensic science BY A. S. CURRY Home Office, Horseferry House, Dean Ryle Street, London SWIP 2A W, U.K. Office,Horseferry (Lecture delivered 26 May 1977 - Typescript received 3 June 1977) The influence of the scientist in the investigation of crime has grown rapidly since the establishment of regional forensic science laboratories about 40 years ago. Eight laboratories with a staff of about 700 now cover the whole of England and Wales and a fictional crime of kidnapping is used to illustrate how the scientist can help the police officer in his enquiries. A broken window with smears of blood on it together with tiny fragments of fibres can reveal a great deal of useful information and the methods of investigation is described; the car the criminals used is defined by an examination of smears of paint on a gatepost, tyre marks in soil and fragments of headlamp lens. The use of computerized information banks dealing with analytical characteristics and their use throughout the country is discussed, together with techniques available for examining traces the criminals may have brought to, or left at the scene. Unsolved problems in forensic science are considered.

INTRODUCTION

I am sure you have all seen in your newspaper the phrase 'forensic scientists have visited the scene '. Some of you may have been on juries in which scientific evidence was given from the forensic science laboratory but I think it would be of help to begin by indicating the size of the crime problem in the United Kingdom. In England and Wales over 2 million crimes come to the attention of the police each year and it is distressing to record that 71 000 of these are offences against the person. This latter figure has doubled in the last ten years and whereas the theft of a radio from one's motor car may not create much more than annoyance it is essential that people should be able to walk the streets in safety and that their houses should be secure from the criminal. Some of you may even have experienced the situation of arriving home in the evening to find all your treasured possessions gone and the house in chaos. The maintenance of law and order is one of the criteria by which society is judged. The responsibility for this rests with the police but they have to act within the confines of the law which is decided by Parliament acting in the interests of society. The police in our country have a reputation second to none but the tightrope between the preservation of law and order and the freedom of the individual is one which has to be walked in such a way that one does not have a police state 7

[189]1

Vol. Igg. B. (14 November i977)

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190

A. S. Curry

on one side or, if one falls off the tight-rope on the other side, complete freedom for the criminal. Police forces in this country have always been in the vanguard concerning the technical aids that could be used to help them in their enquiries. Their use of science goes back over a hundred years but its harnessing on a national scale is only just over 40 years old. It was in the middle thirties that the Metropolitan Police Laboratory at New Scotland Yard was opened and almost simultaneously, regional forensic science laboratories for use by provincial police forces were opened by the Home Office. Organization of forensic science In England and Wales the laboratories are now situated at Chorley, serving the north-west, Wetherby, the north-east, Nottingham the east midlands, Birmingham the west midlands, Aldermaston, the central southern part of England, and laboratories at Cardiff and Bristol, which will soon be amalgamated into a new laboratory at Chepstow, serve the south-west and south Wales. The total staff in these laboratories and the Metropolitan Police Laboratory number nearly 700 people and in 1976 they dealt with nearly 120 000 cases. This is a major operation and indicates the concentration of science in police work. The laboratories are in the process of being rehoused following the consolidation of their work since the 1930s and by the early 1980s all of them should be in purpose built laboratories. The equipment of the laboratories is highly sophisticated and they stand comparison with any in the world. The national organization of laboratories in this country, although not unique in the world, has great advantages over those countries in which science for use by policemen has been concentrated either in small local laboratories or as a part-time occupation of some departments in universities. The scientist coming from university into the forensic science service enters the Scientific Civil Service and has a career structure which can take him to the highest ranks. The ability to provide this career structure coupled with good working conditions and excellent equipment means that the calibre of science applied to police work is extremely high. In addition to the regional forensic science laboratories there is also the Home Office Central Research Establishment at Aldermaston. About 10 % of the forensic science, budget and staff is invested in this establishment. The establishment provides not only a full time research and development capability but also a core of very large instrumentation such as the availability of neutron activation analysis facilities and other trace element analytical techniques such as X-ray fluorescence and spark source mass spectrometry. New techniques which have been introduced at the research establishment such as organic mass spectrometry, radioimmunoassay and flameless atomic absorption spectroscopy, were first investigated there and are now being introduced into regional laboratories use as fast as money is available. The whole service can draw on the research establishment for investigations into the most serious crimes. The research establisment also provides an information service about which I shall be speaking later.

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191

Review Lecture: forensic science

Murder, rape, grievous bodily harm, hit-and-run motor car accidents are the stock-in-trade of the forensic scientist. In addition there are the mundane day to day tasks of analysing blood samples for alcohol from drivers suspected of driving over the legal limit and in the last decade we have seen the drugs explosion. About half the cases coming into a forensic science laboratory concern samples of blood for alcohol analysis and a quarter concern drugs. Although the analyses for alcohol may seem like a factory job it is important to realize that intense monitoring of quality control or, some people would say, quality assurance is an integral part of the work of the forensic scientist. It would be entirely invidious if the service could not show that it in fact had overall high standards and that the results in one corner of the country were the same as those in another corner. This monitoring of performance has been enthusiastically welcomed throughout the service and spreads to all areas of its work. Analytical work on drug identification does not stop there: the very careful analysis of traces of other material in the drug sample very often leads to an indication of how the illicit material was made and in terms of natural products like cannabis and opium it can lead to an indication of the country of origin and indeed enable a monitoring by laboratory work of illegal importations. The liaison between the laboratory intelligence and the Central Drugs Intelligence and Illegal Immigration Unit at New Scotland Yard has developed in this country into the marriage of the mass spectrometer to the policeman on the beat. This is in an area which is increasingly becoming important in the role of the laboratory, that is, the provision to the police of information which is relevant, long before a suspect has been found. The pattern of change in laboratory work will be seen in many areas, in that ten or twenty years ago there was very little the scientist could do until the police had a suspect. The role of the laboratory is now becoming very much more important in indicating to the police the line of enquiry which is likely to be most profitable, and in order to demonstrate this I should like to take as my theme of this talk the investigation of a particular crime which is entirely imaginary. Nevertheless it will I hope, in the short time that I have available, demonstrate some facets of the work that is done by forensic scientists. Investigation of an imaginary crime The crime is one of kidnapping. At 7 o'clock one evening the parents of a young boy aged seven left their home leaving the boy, who was their only child, in the care of a neighbour who lives nearby and often babysits. The parents were going to a dinner and did not return until 3 a.m. The babysitter, having put the boy to bed, went to bed herself in the next room and took some sleeping capsules as was her usual habit. Before going to bed the babysitter checked that the boy was in his room and sleeping peacefully. When the parents returned, they found the bedroom disturbed and the boy missing. The house is a large detached double storey building, set in its own grounds with a double drive with gates that are always kept open. The garden frontage, of about 20 yards, is filled with shrubs which shield the front of the house from the road. Entrance to the house was gained 7-2

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192

A. S. Curry

through the kitchen door. There are glass panels in the door and entrance had been effected by breaking one of the panels, removing part of the glass, inserting a hand and turning the lock from the inside. In the bedroom the bed clothes had been pulled to one side and a torn piece of pyjama material was lying on the floor. The police were informed immediately. A full search of the house and area by 'scenes of crime' officers was made shortly after arrival and the evidence found will be described later. In these situations a special investigation squad is formed as it was apparent that a kidnapping had taken place. The following morning a letter arrived which read 'your son will not be harmed and will be returned to you provided you follow these instructions precisely. Draw ?40 000 in notes - ?20 000 pound notes and ?20 000 in five pound notes. Your house is being watched. We will telephone later. You had better have the money. Do not inform the police of this note or your son will not live another day.' The money was drawn from the bank and following telephoned instructions later in the day, the boy was eventually recovered by the husband of the babysitter. This involved changes of cars in a pub car park and, following instructions, attaching suitcases containing the money to ropes found hanging over a gate, these being pulled over the gate by someone behind. Almost immediately an envelope was thrown over which gave typewritten instructions leading him to the recovery of the boy, who was unharmed. Now I should like to go over this crime to indicate how the forensic scientist can help the police in their enquiries. The laboratory has two roles, first to provide the investigating officer with useful information about the possible person or persons responsible and secondly to provide evidence to convict them if and when they are caught. The first place to look at is the scene of the crime. An examination of the entrance to the house reveals fresh tyre impressions in the soil and from an examination of these it is possible to say, by comparison with a data bank of tyre impressions held at the Central Research Establishment, that one of the tyres on the car was a Dunlop SP180. This gives us some information as to the possible models to which this tyre may be fitted. At the point of entry there is a glass on the floor and by examination of the broken pieces it is possible to say from the striation marks on the edges that the entry had been effected from the outside. A smear of blood indicates that one of the kidnappers had scratched his hand when putting it through the window to open the door. Adhering to the edges of the glass remaining in the window are fragments of fibres presumably from the jacket or sleeve of the criminal. These are very carefully lifted by means of sellotape. An examination at the point of entry reveals several footprints, which after elimination of those of the household and the first police officers, enables the forensic scientist to indicate that there were at least two people involved. The patterns can be referred to the footwear data bank and the size of the shoes measured. In this way we get an indication as to the physical size of the feet of the persons involved. In addition the wear marks provide

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