Criminalistics is a vital element in forensic science. It involves the use of analytical methods in the interpretation of evidence and facts in a criminal investigation, through the use of the natural sciences.
Decades ago, the area of criminalistics and forensic science were in very early stages of development. The processes that were used to solve crime were cumbersome and in many ways very ineffective. It was not common to hear of the use of biological evidence, such as the use of DNA profiling in solving serious criminal cases. Today, however, this is child’s play and as a matter of fact, the area of criminalistics research and forensic studies has moved on to greater exploits in the research of the natural sciences and how it has moved on to discover fascinating techniques in analysing evidence from crime scenes, not to mention the higher probability of attaining accurate results and drawing the most factually proven solutions, based on detailed analysis and scrutiny of the evidence provided.
This paper will be examining in thorough depth, the research methods which should be applied in criminalistics. As scientific advancements occur, the progress made so far, with proven and recent information and how these have affected criminalistics today will be examined in this paper.
Criminalistics is defined as that profession and scientific discipline directed to the recognition, identification, individualization, and evaluation of physical evidence by application of the physical and natural sciences to law-science matters, as affirmed by the American Board of Criminalistics. It involves tremendous levels of research activities in order to draw a conclusive solution to fact provided thereof.
The processes involved in Criminalistics research are numerous and in order to successfully accomplish the task set before the investigator or researchers, these areas need to be thoroughly examined thorough analysis of the evidence presented and all relevant factual information.
This research process involves the details of how to process a crime scene, the collation and documentation of hard and physical evidence, making comparisons between individualization trends, analysis and scrutiny of biological evidence, chemical identification (Gaensslen et al 2008). These areas are to be covered in greater detail throughout this essay.
Processing a Crime Scene
Criminalistics research involves knowing in a broad scope, how to process a scene where a crime has been committed. This is the first step to take into consideration at the scene of any crime. Sgt Hayden, a retired police office in the state of Illinois, described it as intricately multiple-tasked, while at the same time being interwoven together with other functions. With variances in crime scenes, it can be a challenge to be in the know-how with regards to processing the scene of the crime. However, there are fundamental basic concepts which are applicable to all crime scenes and these procedures or protocol need to be adhered to, in order to begin the investigation at the scene of the crime. These steps include conducting interviews, examination of the scene, taking photographic evidence, sketches and finally, processing the information collected.
At the scene of the crime, it is the responsibility of the crime scene technician to interview the victim at the scene and the police officer. It is essential to know what the purported theory behind the crime is in order to gain clues into what actually happened and finding the culprit. The process of examination of the crime scene is necessary in order to verify whether the theoretical assumption is supported by the actual scene itself, through the observations made by the crime technician observes. Photographic evidence is a pre-requisite and gives a record of various pictorial views of the scene. The purpose of this is to identify possible clue. In taking such photos, there are two categories into which it is sub-divided. The first is the overall pictorial view of the crime scene. Secondly, the pictorial view which delves deeply into searching for items of evidence is also essential.
It is the responsibility of the crime technician to take a sketch of the crime scene. For instance at a murder scene, the technician will need to sketch the actual position in which the deceased was found and searching for possible evidences. The last step of all mentioned above involves processing the scene of the crime for testimonial and physical facts. The identification, evaluation, collation of physical evidence to be further analyzed in the crime laboratory are all part of the process which the crime technician must follow-through.
Collecting and Documenting Physical Evidence
In the process of documentation and collection of the physical evidence at the scene of a crime, there are stringent procedures in place in order to ensure uniformity, accuracy in reporting the information and ultimately, efficiently solving the crime. To accomplish these tasks, many law enforcement agencies use specifically designed forms and documentation, for recording the various aspects of the crime scene. An important point to note is that in as much as these forms are designed to be a standard, there are provisions made to vary it. This to a greater degree depends on the complexity of the case and the amount of information which will be required. Therefore, the collection and documentation process should have room for flexibility which is highly dependent on the specific case which is under investigation.
As part of stipulated guidelines, all collection and documentation procedures need to have six important categories of documentation as identified via the crime scene investigator website which include the administrative worksheet, narrative description, photographic log, diagram sketch, Evidence Recovery Log and the Latent Print Lift Log.
The administrative worksheet is used to record any major events, times and movements relating the crime incident. Throughout the course of the investigation, this worksheet will be updated with new information and holds all the vital initial information relating to the crime. The narrative description gives an overall account of the first observed appearance of the scene of the crime upon arrival. It focuses on the general overview and does not delve into specifics of the whole investigation. The log book for photographic evidence records the various views taken at the crime scene, including the close-up, medium and overall views. This log produced, contains the technical and descriptive information which applies to the actual job of taking pictures of the crime scene. For the purpose of administrative and chain of custody purposes, there is also the need for an evidence recovery log. This log records, collects, marks and packages all the physical evidence compiled at the scene of the crime. Finally, there is the Latent Print Lift Log which documents recognized, marked, collected and packaged lifts, that were made of latent prints which discovered at the crime scene.
During the collection and documentation of physical evidence, there will be the need to analyse various forms of trace evidence using different techniques and the use of special illumination techniques and the use of forensic light sources among other methods of locating trace evidence using dye stains, chemical applications and also powders used to dust for finger prints. During the collection process, it is of absolute importance that particles are handled with extreme caution, in order to avoid contamination and loss, not to mention that it might be the most vital piece of information to solve the case and hence there is really no room for errors.
Comparison of Individualization Patterns
Individualization refers to the process of placing an object in a unit category that consists of a single unit. Individualization implies uniqueness (Saks et al). It is further described as the fundamental aspect of criminalistics. (Osterburg 1969). Individualization implies uniqueness by placing an object in a unit category that consists of a single unit. Characterised individualized patterns are crucial in criminalistics and is at the centre of physical evidence. These patterns realize the objective that uniqueness is can be achieved and existent is highly important in the work of forensic science and criminalistics (Inman et al 2001). Gaensslen et al identify the various members that make up this group:
The major members of the pattern group are fingerprints, questioned documents, tool mark, and firearms evidence, and other patterns, such as footwear and tire impressions. This kind of evidence consists of patterns that might be called individualization patterns. Under favorable circumstances, individualization-pattern evidence can be attributed to a unique source. (p 341).
Furthermore, Saks et al recognize the attributes which are distinct to individualized pattern:
This assumption of discernible uniqueness endows criminalistics with important practical benefits. It enables criminalists to assert definitive conclusions in casework. At the same time, it relieves criminalistics of the rigors of developing measures of object attributes and collecting population data on the frequencies of variations in those attributes. It also exempts the various subfields from determining the proper statistical model for estimating random match probabilities, calculating those probabilities in actual cases, and explaining to judges and juries the extent to which different objects could share a common set of observable characteristics. In short, without the assumption of discernible uniqueness, far more scientific work would be necessary, and criminalists would need to offer more tempered opinions in court. (p 206)
This critical work is definitely mandatory in conducting criminalistic research, without which
There will be substantially a lack of vital information.
Analysis of Biological Evidence
In criminalization, biological evidence plays a tremendous role in identifying blood and other physiological material and searches for relational links in order to ascertain or refute an allegation that arises in a Criminal investigation. Biological principles are applied in various degrees in molecular biology, genetics and biochemistry. It is important in crimes which are committed against persons, like assaults, terrorism, criminal paternity, homicide, sexual attacks; mass fatality incidents; Paternity/Kinship claims; motor vehicle incidents and property-related crimes like burglary. As such, there is more often than not, the increased likelihood of the transference of biological material between scenes. The result of which is the establishment of links between the perpetuator of the crime, the actual weapon and the victim. This evidence could be in the form of bodily fluid like blood, urine, semen, saliva, vaginal secretions, hair follicles among others.
By using various techniques, the DNA evidence can be discovered through the thorough analysis of the biological evidence. These include the use of DNA Profiling, Y-STR analysis, Y Chromosome Analysis, Low Copy Number (LCN) Analysis, mRNA Expression Profiling among others. It is important to know how to apply these techniques, depending on the circumstances and the complexities involved in the case.
In analyzing biological evidence it is important to note that adequate precaution has to be taken in order to avoid loss of vital information. Assessments and In Vitro Repair of Damaged DNA Templates in Biological Stains, analysis of the biochemistry in a dried state and double strand break repair need to be carefully conducted in order to optimize results. There are limiting factors with DNA typing technology can so cause damage, which makes it intractable to any
kind of analysis whatsoever. Biochemistry of the Dried State examines the basic chemistry of the dried state, specifically oxidation and hydrolysis, which are the most common expected type of chemical reactions. In performance of tests such as kinetic analysis of dry state, the degradation of the DNA can be determined, especially when subjected to various environmental conditions. With efforts also on hydrolytic damage to the relatively labile glycosidic bond and deamination of the nitrogenous bases, this approach to biological evidence analysis enables reactions to be determined and thereby paving the way for other quantitative analysis and measurements to be conducted.
Biological evidence uses ‘genetic eye witness’ to unravel crimes of varying proportions. Through comparisons at of the DNA profile at the crime scene, various profiles obtained from reference samples obtained from known individuals are tested to ascertain probable suspects. Examples of other physical characteristics that can be recognized may be amenable to molecular genetic analysis. These include hair-, skin-, stature (weight and height), eye- color, facial morphology and the age.
It is important to note that the National Institute of Justice has issued in collaboration with numerous bodies responsible for law enforcement, have issued the usage of reference documentation which are to be used as part of standard procedures in the collection and protection of the biological samples. These standard documentation serve as reasonable guidelines and outlines by providing a ‘chain of custody’ for respective criminalistics users. This is irrelevant of the fact that they do not necessarily provide any traceable methods. The forensic magazine defines a chain of custody as ‘a crucial component of jurisprudence that is applied to the handling of all evidence and is required for evidence to be admissible in any U.S. Court. (p 1)
In conclusion, criminalistic research is a very broad and yet encompassing aspect of criminalistics, which covers vital aspects in unraveling crimes. Through the delicate and sensitive nature of the procedures involved, it has to be thoroughly conducted, in a very professional and time-sensitive manner. As has been discussed during the course of this essay, crime scene evidence tends to degenerate very rapidly and without proper and adequate measures to safeguard this vital information, contamination will occur. There is therefore the need to apply the most suitable and safe methodologies in ensuring effective conduct of the research in order to conduct a proper examination of the crime and provide the most scientifically and medically sound evidence.
Identification of Chemicals
In conducting research into criminalistics, the ability to correctly identify the different types of chemicals is essential. These types of chemicals differ from one crime scene to another. It involves the usage of Modern Mass Spectrometry to Forensic investigations, the use of oxy-Acetylene on debris from crime scenes, identification trace element distribution patterns and their applications in alcohol and the use of re-ablation methods on crime scene material. In addition to these, criminalist research also involves the use of isotope ratio mass spectrometry in analyzing ignitable liquids and plosive devices; the use of stable isotope analysis in identifying original explosives, the use of ToF-ICP-MS in isotope ratio analysis of artefacts and analyzing forensic material using LA-ICP-MS.
The criminalist research also involves knowing how to identify colored textile fibres from washing machines as well as the use of background correction in forensic photography.
The use of infrared chemical imaging in Criminalistics research is also very vital. This research also makes use of the Capillary Electrophoresis when analyzing personal items which may include clothing, condoms among other personal items. It is also important to know about the solid phase micro-extraction techniques which are used in detecting the presence of explosives.
In the detection of stains on fabrics ad similar items, there is the need for the researcher to identify the various types of chemical dyes which are used in respective fibres. Different types of fibres do require different dyes in order to ascertain specific types of evidence, for instance different types of bodily fluids. Hence, the need to be able to identify these chemical compounds.
These are some of the areas of identification that require the specialist work of the criminalist. Therefore, in order for the criminalist to optimally perform the requirements of the criminal case, it is essential that thorough research is performed. Due to the numerous kinds of criminal cases and the differences in complexities, it should be expected that some chemical identification should be done and sometimes there may be a greater requirement of some, more than other. It is therefore imperative that these chemical identification techniques must be known, in order for a thorough and professional conduct of the specified criminal case.
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