‘Forensic science is science used for the purpose of the law’ (White 2010), it has three main phases, which are, the recovery of evidence from the crime scene, forensic examination of the evidence at the laboratory and the presentation of evidence test results in court (Jackson 2008). A crime scene is any location or locations which contain evidence that can help with a criminal investigation. Therefore, a crime scene can take many forms, it can be indoors or outdoors, i.e. a road accident or a burglary and it can consist of just a finger mark or it can include acres of land. Subsequently, many types of evidence can be found at a crime scene, from the smallest fibres which are invisible to the naked eye, to something as obvious as a broken window. It is up to the scene of crime officers (SOCOs) to gather relevant physical evidence to send to the forensic laboratory for further examination (Jackson 2008). Forensic laboratories are either provided within the police service (known as the forensic science service department (FSS)) or by independent forensic services which offer different areas of expertise depending on specialist equipment and expert scientists in any given field (Jackson 2008). Hence,
forensic laboratories cover a broad area of expertise which include: Pathology, which would for example be involved in case’s of rape or unnatural death; firearms experts, who among other things would be involved in examining bullets found at a crime scene; and questioned documents experts, who would be involve in cases of fraud (Eckert 1996). The forensic scientist is responsible for providing a report of the evidence that can used in court, it must be written so that those that are unfamiliar with scientific terms can still understand the conclusion of the results. This essay aims to explore the importance of the work carried out at the crime scene in comparison with the work carried out by the forensic laboratory, in order to establish whether the crime scene is the most important area of forensic science.
The crime scene is important because, if dealt with carefully, it can provide the physical evidence which is needed to build a criminal case against a suspect. The evidence recovered from a crime scene can be used in various ways, including: to establish if a crime has in fact occurred, as this is not always obvious at first glance, for instance, in the case of a fire scene it would need to be established if the fire was started either accidentally or deliberately; identification, evidence can help to identify the victim, offender and any other persons that may be involved in the crime; To corroborate or refute statements and to gather intelligence in order to make associations between different crime scenes and to find any links between the persons involved (White 2010). In order to produce such crucial evidence a crime scene is generally separated into two categories depending on the seriousness of the crime committed; less serious crimes such as burglary would be classified as a volume crime and more serious crimes such as murder would be classified as a serious crime, and so crime scenes which involve volume crimes are typically investigated by a lone scene examiner and serious crimes typically involve a team of scene examiners (Jackson 2008). Only reliable and impartial evidence can be used in court, therefore the evidence samples recovered from a crime scene need to be properly handled, preserved, packaged and transferred throughout the whole process of investigation. This careful process is known as the chain of continuity and needs to be demonstrated in order for the forensic laboratory to gain valid evidence which can be used in juridical proceedings (White 2010).
Therefore, in order to recover valid and useable evidence the most important rule of a crime scene – after preserving life – is to preserve the scene of evidence in order to prevent contamination (White 210). The crime scene must be defined, secured and cordoned off, allowing as few people as possible entry and a scene log should be used to record those that do enter. Inside the perimeter of the crime scene a forensically cleared ‘common approach path’ (CAP) is established by using either scene tape or stepping plates or a combination of both. The CAP enables access to the investigators whilst preventing contamination of the evidence by keeping everyone to a designated route which avoids disturbing that of the offender whenever possible. Also, anyone who enters the crime scene must wear protective clothing, including over-shoes, gloves (preferably two pairs as the first can be contaminated just by putting them on), scene suits, head covers and masks, which must always be changed into before entering or leaving a crime scene. This is to prevent foreign matter being brought into the crime scene and also to prevent evidence from being transferred elsewhere; both of which can compromise the investigation (white 2010). The crime scene is the ‘first link in the chain of investigation’ and if any evidence is compromised then so is the whole investigation. Therefore, In order for evidence to be used in court it must be carefully and systematically handled throughout the investigative process; the continuity of evidence must be sustained from when it is recovered at the crime scene, throughout its transference to the forensic laboratory and then into court, where the evidence will be scrutinised by the defence (Eckert 1996).
The forensic laboratory is an important part of the criminal investigation because it examines the evidence that is found at the crime scene and on victims and suspects, in order to find a link that can be used as expert evidence in court. Forensic examination aims to validate the evidence found at the crime scene with scientific proof that can withstand harsh cross-examining in court. Forensic analysis can support a criminal investigation in many ways, among others, it can prove that a crime has been committed, by identifying drugs or alcohol in a person’s blood stream, it can provide investigative leads, for example, by identifying a blood type or shoe size, and it can help identify a suspect via DNA in seminal fluid (Jackson 2008). Laboratories offer different fields of expertise depending on the many different types of evidence they examine (Eckert 1996). For example, the toxicology and drug identification laboratory would be used to test drugs and poisons and the forensic serology laboratory would be used for the analysis of body fluids, such as blood and semen (white 2010). Therefore, the laboratory plays an important role in the investigative process, but unless due care and continuity has taken place to preserve the evidence at all stages of the investigation, i.e. preservation, documentation, storage and transportation, then the work carried out at the laboratory is discredited..
Therefore all recovered evidence must be carefully labelled and stored appropriately, different sample types must be stored in different ways, for example, blood stains need to be air dried before packaging so as to avoid bacterial activity which can hinder the analysis (Eckert 1996). Continuity forms, notes and labels must be properly filled out and it is important that the relationship between the physical evidence and the crime scene is maintained, through photographs, diagrams and written notes. Also, good communication between the SOCOs and the laboratory examiners is important in developing a good understanding of the crime (Jackson2008). The crime scene is the ‘first link in the chain’ and the whole of the forensic investigation process can be rendered useless if the correct procedures are not followed. Therefore, continuity throughout the whole process of investigation is paramount in order to keep the validity of the evidence so that it can be used in juridical proceedings.
The crime scene is an important area of forensic science because it is the starting point of the whole criminal investigation, all consequent areas follow on from it and if mistakes are made here then there will be repercussions throughout the whole process. The crime scene is the most important area from which evidence samples are gathered because without this evidence the forensic laboratory would have nothing to work with. Conversely, without the scientific skills of the laboratory much of the recovered evidence would be fruitless; some evidence can be analysed without a laboratory but it takes more time and is less efficient.
In conclusion, both the crime scene and the forensic laboratory are important areas of forensic science and when they work together effectively they can be the deciding factor in a criminal court case. However, even without the use of a forensic laboratory the crime scene would be a useful source of evidence but in contrast the forensic laboratory would be rendered useless without the evidence samples that are supplied from the crime scene. Consequently, the crime scene is the most important area of forensic science.