Crime Scene Investigator (4 page)

Sir Edward Henry introduced the fingerprint system in Scotland Yard in 1900. A collection of inked finger impressions (fingerprints) formed the basis of the method of identifying individual convicted criminals along with their criminal record history. It exists to this day. Finger impressions (finger marks) recovered from crime scenes formed a later collection. At first manually stored and now computerised, these can be searched against the prints of those with previous convictions. It is a powerful tool only to be matched in its impact in the scientific investigation of crime by DNA technology, almost a century later.

The Frenchman Edmund Locard is the modern father of forensic science. In the early 1900s he formulated his ‘principle of exchange’ which is the cornerstone of the science to this day. He stated, ‘When two objects meet there is a mutual exchange of material from one to the other.’ It can be summarised to say ‘every contact leaves its trace.’ The challenge is to find it.

However, finding it is only the first part of the problem. Once found, we have to consider its meaning. Forensic science can be said to be the science that brings all science together and then brings it into the courtroom. Which is where the term forensic originates, its means ‘pertaining to the law’. Forensic science is the science of identification, contact and dynamic events. Above all it is a science of context. Many events which forensic science may detect can be ordinarily found, perhaps innocently, in everyday aspects of human endeavour. What makes these events evidence in a criminal trial is the context in which they are found. The finding of forensic evidence can indicate the presence, actions and consciousness of an individual at a time or place which supports their involvement in the commission of a crime. It can also exonerate, which is often its most important use.

The Metropolitan Police Forensic Science Laboratory opened in 1935 at Scotland Yard and marked the beginning of a planned use of forensic science in criminal investigation in the UK. Home Office laboratories followed to serve provincial forces. By 1959 a new profession of forensic science was establishing itself, prompting like-minded individuals to form the Forensic Science Society. Its aims were to ‘advance the study, application and standing of forensic science and to facilitate cooperation among persons interested in forensic science throughout the world’. It has been doing that pretty effectively ever since.

The specialised examination of the crime scene is an even more recent event. Until the 1950s in the UK and North America, the examination of the scene was the domain of the detective. Only rarely, in numbers which could be counted on one hand, would forensic scientists themselves examine a crime scene and then for a single purpose, most commonly for something like blood splashing. Pathologists had for many years examined the scene of sudden or suspicious death but their domain was that of forensic medicine and toxicology. It didn’t stop many of them from stepping into areas in which they had no training or experience. In the absence of dissent, their medical expertise in all matters forensic was accepted unopposed.

The regular and routine examination of crime scenes for fingerprints by specialists began with the Metropolitan Police in London with the introduction of civilian fingerprint officers in 1954. Up to that time it was the sole domain of detectives with varying degrees of interest and skill. In 1966 Humberside Police employed the first civilian scenes of crime officers, followed by the Metropolitan Police in 1969. Other police forces in the UK followed suit using a mixture of civilian and police personnel. The term scenes of crime officer or SOCO became synonymous with the role. Other police forces (such as Durham) used the term scientific aids, but soon came in line with the rest of the UK.

The role was seen as one of crime scene examination for a number of years, which belied its full impact within the investigation process. That was not good enough as far as I was concerned because it failed to recognise the integration of science within the whole investigation. Dave Werrett (a pioneer in the introduction of DNA technology into forensic science and who later become head of the UK Forensic Science Service) used the phrase which I always liked. He referred to the ‘continuum’. This aptly describes the seamless process from crime scene to court. Many players take part in the process but it should have one purpose and goal. To me it was always a matter of escalation, from the first patrol officer who attended the crime and realised there was something more than they could handle, to the detective and the specialist crime scene person, to the specialist scientist in a particular evidence type. Each adds his or her own knowledge, training and expertise to the problem until a definitive answer can be found. The crime scene investigator is in real terms a compromise. They are the eyes and ears of the expert scientist in every conceivable field. It isn’t possible or practical to regularly bring every expert to the scene to conduct their own examinations. This is not to say that experts never attend scenes and examine areas specific to their expertise. They do. They are called as part of the escalation process when the scene investigator establishes that the scene is beyond their own skills. As a crime scene investigator I needed to maintain a crust of knowledge of all the forensic science disciplines and be able to handle new ones. This I could do by holding to core principles whilst seeking advice from wherever I could get it. Compromise may be a harsh description of a scene investigator, but that is how the role started out. It understates the investigative role which has added immense value to criminal investigation and has developed now into the management of the scene investigation process.

The standard text
Techniques of Crime Scene Investigation
, first published in the 1950s, was a bible to me but even it did not demonstrate the application and dynamics of the investigative team and process. This comprehensive textbook fully explores the techniques I would use in crime scene examination, but did not explore the communication and interaction with others that I saw as true investigation. By 1989, when I led the development of the Forensic Science Society diploma, there was no doubt in my mind that we were testing scene investigators and not just scene examiners. So against some resistance (well quite a bit actually, as I will explain later), the Diploma in Crime Scene Investigation was born.

Forensic science is not just about fingerprints and blood, which are often seen as the easy options, giving the highest returns. Any contact trace or residue which can prove a crime has taken place or link an offender should be considered.

So the toolbox of the crime scene investigator is full of technologies and evidence types: paint, glass, shoe marks, tyre marks, bite marks, ear marks, blood, semen, saliva, urine, hairs, fibres, firearms residues, toxicology, poisons, ballistics, pollen, vegetation, fire accelerants, inks, latent marks and impressions, physical and mechanical fit, computers, light sources and many more.

All these technologies are worth nothing without much more important tools. Technologies continue to improve and changes in legislation necessitate finding new ways to enforce our laws and detect when they have been broken. However, the enquiring mind and the ability to listen and question are the most important qualities of an investigator. The answers to questions such as who, where, when and why remain unchanged. When these answers are sought, only then can the quest to methodically search, test, recover, record, review and evaluate evidence begin. The final question is to determine what it all means.

The sound of wailing sirens pierced the hot and humid air coming through the office window. It was a balmy sunny evening and I was looking forward to clearing some paperwork. Late turn on G Division meant covering the three police stations in the London Borough of Hackney up until ten pm, after all my colleagues had gone home. Any thought of a quiet evening, perhaps examining a couple of burglary scenes and enjoying a quick pint next door at the Eagle before going home, disappeared when the phone rang.

It was a detective sergeant calling from the CID office at Stoke Newington. He was investigating an allegation of a racial attack on a West Indian woman. It appeared that someone had put a lighted petrol bomb through her door. He asked me to attend. It was serious so I had no hesitation.

I didn’t enjoy driving through the weave of traffic as London commuters made their way home. It was only a few miles after all, but it can seem like ten times that and it would probably have been quicker to walk. Stoke Newington was the biggest police station on the Metropolitan Police’s G Division. Its CID office boasted about thirty detectives, although only a handful were on duty at any one time. It was a hard place to work and tested every part of your professional existence. It had a very high crime rate and the range of crime tested every part of your training. All life was there. It was a grand area with tree-lined Victorian avenues which had seen many changes. Once the domain of the emerging middle classes, boasting the names of theatre land as its occupants, it had been swallowed up as London expanded and was now most definitely inner city. A large influx of immigrants from Europe and latterly the West Indies made it a racial melting pot. Hassidic Jews, the men in their black robes and brimmed hats covered in plastic to keep them dry, lived in grand houses in areas surrounded by postwar council flat developments.

The area had seen much redevelopment since the end of the Second World War. Although the blocks of pre-war flats with their concrete courtyards still existed, new blocks of large, imposing council flats on green estates were emerging, providing good accommodation with a more pleasing outlook. Even that was not enough to take away the tension of inner city life and the close proximity of neighbours.

I met the detective at the scene. By the time I arrived it was already after eight pm. I parked my van at the foot of the block of flats. The building was a pleasant-looking 1970s-built apartment block. It had about five levels and all the front doors of the flats opened directly out on to the front balcony with an impressive view on to the car park and grass areas below and over the rooftops of older but still well-maintained houses across the way. The scene was on the fourth floor. There was a feeling of space. It was clean and even the lift (which worked) didn’t have the usual smell of urine which was the norm in many similar complexes. I sensed that the occupants of this building took care to look after it.

When I arrived at the front door to the flat it was open. I could see some scorching to the outside of the front door around the letter box. The fire damage inside was worse but limited to the rear of the door, with a little smoke damage extending at a high level along the hallway area. Looking inside, down the hallway, I could see the detective sitting at a kitchen table with the victim, a middle-aged black woman. The detective was taking a statement but broke away when he saw me. I apologised for the interruption. He explained to me that the lady stated that she had received some racial threats over a period of time. Today, a lighted object had been pushed through the letter box. The victim was in at the time and had quickly put out the fire. The potential threat was serious as, had the fire spread, it would have been potentially life threatening. Being on the fourth floor and with the hallway on fire, she would have had only the front window as a potential escape route.

The detective then drew my attention to a small, heavily blackened bottle complete with charred paper wick. The contents for some reason had been poured down the drain by the first officer at the scene, apparently for some safety reason which made no sense to me at the time. A note for future training, I thought. There was still a drop of liquid which smelt of spirits.

The detective then returned to the victim to continue with the statement whilst I began to examine the scene.

Although the door was on a public landing it still required examination for finger marks, for accuracy and thoroughness if for nothing else. The contents of the bottle required identification and the bottle and the wick would need fingerprint examination. Although now burnt and covered in spirit this would be very important, as it was a direct link to the offender.

I completed a full visual examination, making some initial notes and diagrams before beginning to preserve the bottle and its contents.

There was something which worried me. The glass bottle was indeed small, but the letter box, although a little larger, was restricted by a poorly fitting flap, which severely reduced the opening aperture. I measured both before offering up the bottle as carefully as I could so as not to disturb any finger marks. It didn’t fit and that was obvious. No matter how I tried, this glass bottle was not going to go through the letter box. Nor had it done in the past. This changed the situation completely.

I went into the kitchen and stood by the detective as he sat with the victim at the kitchen table. Looking around, I noticed a neat row of spice jars each one of them identical to the now blackened jar at the front door. And to add to this there was a gap.