The Importance of Trace Evidence in Forensic Investigations
Abstract
The paper focuses on the concept of trace evidence and explains how it is used to solve cases. Since people interact with multiple objects, their tiny particles are attached to individuals and their clothing. Investigation of scientific and academic sources reveals that there are different types of this phenomenon.
Suitable examples refer to soil, glass, paint, fibers, biological materials, and gunshot residue. Each of them requires a particular analysis method to determine the composition and other peculiarities of the collected sample and find its connection to a suspect. The findings of this report demonstrate that forensic professionals can use trace evidence to receive valuable and objective information to find a criminal. That is why investigators should draw much attention to the element under analysis to improve their efficiency and solving rate.
Introduction
Investigators should typically collect and analyze large volumes of information to solve a crime. In some cases, evidence is easily found to retrace the events and determine a suspect. In other situations, law professionals are encouraged to deal with trace evidence to achieve their goals.
This term is used to define any materials of tiny size, which allows these pieces of evidence to be transferred when two objects establish contact with each other. Even though these elements are extremely small, they can provide investigators with efficient and valuable information to identify who and how has committed the crime under analysis. Thus, there are different kinds of trace evidence, and inspectors should attentively look for and consider each of them to find answers to their questions and solve a case.
Discussion
To begin with, one should explain that trace evidence is an unavoidable phenomenon. As Locard’s exchange principle stipulates, “contact or interaction between people or between a person and a place inevitably produces some type of exchange of material between them” (Bell, 2019, p. 15). This information is good for investigators because it demonstrates that if a person has committed a crime, there are certainly some elements that can prove this fact. The task of crime scene explorers is to find and interpret these particles. Since trace evidence is tiny, various kinds and techniques of microscopy are used to cope with this task (Bell, 2019). These methods allow for locating different types of trace evidence, which will be discussed below.
Types of Trace Evidence
Glass
In fact, any material can be considered an example of trace evidence. Glass is the first type that will be discussed in this paper. This material is characterized by various sizes, shapes, and colors. Since glass items are widespread, forensic professionals should understand what information can be retrieved from them.
For example, when a glass window is broken at a crime scene, the investigator can study the composition of this material and compare it to glass particles found on the suspect’s belongings. The presence of these fragments will present strong evidence to claim that a person attended the crime scene.
In addition to that, specific attention should be drawn to glass fracture patterns because radial and concentric cracks can reveal when and how the force was applied to the object. For instance, such fractography analysis can help identify the point of impact, direction of force, and force magnitude (Brooks et al., 2020). This information will further allow for determining the specific weapon or tool that was used to break glass. That is why professionals can retrieve much useful information from glass objects.
Fiber
Fibers refer to the second manifestation of trace evidence deserving analysis. This term is rather broad since it includes clothing, carpets, and other textiles. The leading characteristic feature of these materials is that they can absorb substances. That is why investigators are instructed to collect this trace evidence and conduct their microscopic analysis to arrive at the elemental composition.
Furthermore, Bell (2019) mentions that X-ray and polarizing light microscopy are requested methods used to deal with fibers and their significance. Chemical analysis is additionally important because it indicates what manipulations were exerted toward the trace evidence.
Paint
Paint evidence represents another widespread example of trace evidence that is frequently sent to forensic laboratories. This material typically forms an upper layer of various objects, including vehicles, architectural buildings, and interior objects (Brooks et al., 2020). Thus, when people interact with them, a paint chip can become an outcome of this engagement.
This statement denotes that forensic investigators should compare evidence obtained from suspects to paint samples that were collected at a crime scene. According to Bell (2019), a complete physical match is perfect proof, but if it is absent, inspectors should analyze the paint’s color, structure, thickness, and angle cuts. Infrared microspectrophotometry is the most requested method of paint analysis, and it can help obtain much useful information.
Thus, it is reasonable to mention specific examples of how paint analysis can help solve cases. This approach is useful in housebreaking crimes where paint chips from a door frame or burglarized safe are attached to criminals’ belongings (Brooks et al., 2020). In addition to that, the given kind of trace evidence is extremely useful when stolen vehicles are involved. Brooks et al. (2020) explain that paint analysis can reveal whether a car or its separate part was recolored to hide any information. That is why investigators should carefully and attentively approach this type of evidence.
Soil
Soil is an important kind of trace evidence since it can be very helpful. Bell (2019) stipulates that soil has a unique composition in a particular area because the presence and amount of minerals, residue, and pH are determined by multiple conditions. Investigators use light microscopes to study the samples and make reasonable interferences. In particular, this type of trace evidence can help determine whether a suspect attended the crime scene (Bell, 2019). For that, forensic professionals should collect soil from this site and find identical particles on the suspect’s shoes or tires of their vehicle.
Gunpowder
One should additionally comment on the importance of gunshot residue. When a firearm shoots, tiny particles of metal and gunpowder are released and attached to everything that is close to the gun (Bell, 2019). That is why forensic scientists use a specific device with an adhesive coating to identify these particles. They tend to analyze various surfaces, including skin, clothing, furniture, and other objects (Bell, 2019). Positive investigation results can reveal that a suspect used a firearm or that somebody shot at the site under analysis.
Biomaterials
Some biological materials can be considered trace evidence as well. This statement refers to skin and fingernails that can be found at the crime scene. Brooks et al. (2020) offer a few cases describing how this type of evidence can help solve a case. On the one hand, examiners can collect skin samples and determine a physical fit with a suspect’s material (Brooks et al., 2020). Serological testing is typically used to make the obtained results objective.
On the other hand, fingernail fragments can be informative because forensic inspectors can compare them to the suspect’s nail plate. In one case, a physical fit between a sample and the damaged edge of a person’s nail allowed law enforcement officers to find the criminal (Brooks et al., 2020). This information again proves that attention should be drawn to all possible clues.
Cosmetics
Lipsticks represent the final example of trace evidence that is discussed in this paper. Sharma et al. (2019) stipulate that spectroscopy of this evidence can establish a robust connection between a person and the crime scene. Forensic scientists should collect the samples and analyze their composition to be able to determine whether a suspect uses an identical cosmetic. Thus, a person always leaves traces, and forensic investigators should find and interpret them.
Conclusion
The paper has demonstrated that trace evidence is a significant and informative concept in the sphere of forensic science. Professionals should look for tiny particles because these elements, irrespective of their size, are unavoidable and can convey important meaning to solve a case. Trace evidence can be of different kinds, including glass, fibers, paint, soil, gunshot residue, and various biological materials.
Investigators are encouraged to find and analyze these samples because they help them determine what occurred in a crime scene and what relationship a suspect has to this site. Examiners can find responses to these questions using multiple investigation methods, such as fractography analysis, X-ray, and polarizing light microscopy. This information demonstrates that trace evidence can help forensic scientists solve cases and find criminals.
References
Bell, S. (2019). Forensic science: An introduction to scientific and investigative techniques (5th ed.). Taylor & Francis.
Brooks, E., Prusinowski, M., Gross, S., & Trejos, T. (2020). Forensic physical fits in the trace evidence discipline: A review. Forensic Science International, 313, 1-19. Web.
Sharma, V., Bharti, A., & Kumar, R. (2019). On the spectroscopic investigation of lipstick stains: Forensic trace evidence. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 215, 48-57. Web.