The Effectiveness of Different Brushes - Term Paper Example

Title: THE EFFECTIVENESS OF DIFFERENT BRUSHES IN TERM OF FINGERPRINT RECOVERY By: Institution: Course: Instructor: Date Objectives The general approach to fingerprint detection at the scene of crime is to apply techniques initially, to transport items back to the laboratory for processing. This should be followed by treating the remaining surface with a suitable development technique. Surfaces which are porous, for instance wallpaper can be treated with a ninhydrin solution (PEPPER 2010, pg3). Chemical processing with a technique such as the iodine/benzoflavone spray is the most recommended when it comes to scenes with a more serious nature. Where there are blood marks, then it is appropriate to use blood enhancement reagents (PEPPER 2010, pg13). Fingerprint detection should not be considered in isolation from other forms of forensic evidence. Utilization of any technique that can provide contrast between fingerprint and background is of great importance. Taking these factors into consideration, this research’s main objectives are: To determine the effectiveness of different brushes in term of fingerprint recovery To determine the sequencing of fingerprint detection techniques with other forensic procedures To determine the importance of fingerprint recovery in a crime scene To unveil the types of fingerprint evidence that may be encountered To determine the detection of fingerprints on porous and non-porous surfaces to maximize fingerprint evidence recovery from crime scenes to deliver Home Office objectives in relation to Home Office values to support police force fingerprint laboratories to help in providing the best practice advice on the most effective development techniques and sequences that can be used in fingerprint recovery. To deliver ways in analyzing fingerprints without the need to be a trained fingerprint expert. Summary Identification of humans is a prerequisite of personal, legal and social reasons. Traditional methods of personal identification include dactyloscopy, sex determination, anthropometry, postmodern reports, measurements of height, differentiation by blood groups and postmodern reports. In numerous occasions, these methods have yielded positive results. Criminal investigation is a complex process that involves identification of both murder victim and suspects (PEPPER 2010, pg5). In the current century, the most commonly used scientific methods of forensic identification are fingerprints and dental record. Specifically, fingerprint detection has improved significantly during the past 20 years as a result of efforts made by several research groups across the globe. A wide range of optical, physical and chemical techniques is available for the detection and enhancements of fingermarks. The best fingerprint results are realized with a proper application of logical sequence techniques (PEPPER 2010, pg9). The utilization of more than one technique or reagent mostly enhances the number of prints detected, or to some extent improves the quality of those already developed. Nevertheless, it is factual that each process is applied in a systematic, predetermined order as the incorrect choices or application of one method can produce the later use of another technique or reduce its effectiveness (PEPPER 2010, pg17). The choice of the best brush in fingerprint recovery depends on several factors such as; the nature of the surface such as smooth, porous, rough or non-porous surface; environmental factors such as whether or not the surface is wet; the presence of any particular contaminants for instance blood; and the likely age of any evidential fingermarks. There are three main types of finger print that maybe present at a crime scene. The 1st case comprise of the indented fingermark (PEPPER 2010, pg10). This is a 3-D fingertip impression in a malleable substance such as candle wax. Its effectiveness can be improved through the application of oblique lightning. The 2nd type of fingerprint evidence is the visible fingermark. Enhancement of the visible fingermark is mostly achieved optically depending on the properties of the contaminant in question. The 3rd type of fingerprint evidence is the latent fingermark. These marks are largely invisible and hence some form of physical or chemical treatment may be required to differentiate them from the substrate material. The detection of fingermarks is actually a quite challenging analytical task (PEPPER 2010, pg14). Therefore, proper analytical tools are of essence. Some detection techniques are effective on some surfaces but not on others. This forms the baseline for this paper. In this regards, this paper aims at determining the effectiveness of different brushes in term of fingerprint recovery Technical summary Criminal offenders are most of the time very cautious not to leave any traces at the crime scene and on the handling objects. As a result, crime investigating experts are most of the time faced with the fingerprint tasks, where the conventional, new and improved fingerprint detection methods are used. Generally, whenever a crime is reported, the most obvious piece of evidence that experts look for is the latent fingerprint. The word “latent” is used to show that the fingerprints are not readily visible to the naked eyes (PEPPER 2010, pg56). A crime expert has to process the evidence for latent fingerprint with powders or chemicals. The latent fingerprints can be developed to the where they are easily visible. Apart from latent fingerprints, there are the patent and the plastic or molded fingerprints. A patent occurs as the result of transferring a foreign coating the skin of the fingers, while a plastic or molded impression is deposited when the hands, fingers or feet is pressed into a soft rubbery type material that will retain the impression of the ridge rail (PEPPER 2010, pg15). Knowledge of the various fingerprint collection techniques is vital for successful cross-examination of crime scene technicians and fingerprint examiners. Fingerprint development cannot be considered in isolation. In addition, development techniques can sometimes be sensitive but are impractical if development marks cannot be successful imaged. Therefore, there is a dire need to consider illumination and imaging in addition to development (PEPPER 2010, pg99). In most cases the crime experts are faced with the responsibilities of recovering latent fingerprint (PEPPER 2010, pg37). In recovering the fingerprints there are several products available for the task. The techniques can be broken down into 4 simple areas. The current techniques utilized in recovering latent impressions are florescent die stains or powders. These methods are basically mechanical and chemical in regards to development (PEPPER 2010, pg75). The chemical methods are laboratory based where a variety of chemicals are produced to react to certain components that make up the ridge deposits. This process mostly applies to porous, absorbent items such as paper, matter and untreated wood, semi-porous finished items (PEPPER 2010, pg181). However, this paper will not dwell much on chemical process or rather it will focus mostly on mechanical development in fingerprint recovery. Mechanical development in fingerprint recovery entails the use of a brush and powder to physically dust the surface. It is a technical process that allows for the particles of the powder to adhere to contaminates which caused the ridge deposits. This technique is effective to nonporous items and surfaces. Fiberglass, Camel hair and feather brush are the three main brushes manufactured for the use of mechanical ridge detail development (PEPPER 2010, pg21). Latent print visualization with powder or dusting comprises of the application of finely divided particles that physically adhere to the aqueous and oily components in latent print (PEPPER 2010, pg61). Dusting is relatively simple but majorly relies on the adherence of powder to the latent print residue for quality visibility. The pigment in fingerprint powder enhances the visualization, offering contrast and definition against the background surface. Visualization will occur through reflected light and luminescence (PEPPER 2010, pg23). Sometimes powders are combined for effectiveness on both light and dark substrates. For instance, the bichromatic powder which uses highly reflective aluminum powder mixed with black powder to achieve visualization on both light and black surfaces (PEPPER 2010, pg34). One of the most common latent print powders is carbon black. It is characterized by effectiveness and versatility (PEPPER 2010, pg115). When mixed with a carrier, carbon black works on a wide range of surfaces and causes little substrate paintings. Powders are basically applied to nonporous surfaces with a soft brush. The softness of the bristles is vital for prevention of damages to fragile latent print residue (PEPPER 2010, pg73). It is worth noting that latent prints with high moisture content or oil content are exposed to damages by a brush that is too stiff or is used with excessive force. The 21st century brushes are made with animal hair, fiberglass filaments or sometimes feathers. Powders applied with a traditional filament brush consist of very fine particles and are usually low density in nature (PEPPER 2010, pg41). This is of great importance because it enables the particles to be picked or easily loaded into brush filaments. In addition, the existence of the low density of the powder is responsible for allowing the brush to be airborne during the dusting process, making a dust mask or respiratory necessary at the crime scene. Brushing is accomplished with light and even strokes that resemble painting (PEPPER 2010, pg89). To minimize fingerprint damage, it is of great essence to always begin by lightly powdering and slowly building to heavier applications. Gantt chart Academic beneficiaries In the late 19th century, fingerprint identification emerged as an important system within police agencies. Up to date the importance of fingerprint identification is unquestionable. Fingerprints collected at a crime scene or on items of evidence from a crime are used in forensic science. The science of fingerprint identification has been and will continue to asset standing amongst forensic sciences for several reasons. It is also worth stating that fingerprinting was the foundation through which the first forensic professional organization was formed. That is, International Association for Identification in 1915 (PEPPER 2010, pg121). The first professional certification program for forensic scientists was established in 1977. The International Association for Identification’s certified Latent Print Examiner program-responsible for issuing certificates for the qualified forensic scientists and revoking them whenever one fails to meet the set standards- is a vital organization to ensure ethical standards in fingerprints identification (PEPPER 2010, pg132). As mentioned above, these explanations show the importance of fingerprint identification in relation to academics. That is, it is a field that develops professionals’ right from the start. To be an expert in fingerprint identification, then strong academic background is of great importance. Impact Several new fingerprint development techniques have exhibited improved performance as compared to RCMP standards. Fingerprints have been studied for uniqueness, identification and criminal importance for more than a century (PEPPER 2010, pg134). The importance of fingerprints identification and criminal justice cannot go unnoticed. These two implicate the guilty through linking a criminal to the victim and the scene of the crime and exonerate the innocent. With the emerging technology and well trained experts, fingerprints are definitely considered one of the single most important pieces of evidence for solving a crime (PEPPER 2010, pg145). Databases such as Automated Fingerprint Identification System (AFIS) have been created as ways of assisting the fingerprint examiner during the identification process. These kind discoveries help in delivering a quicker way to sort through unlikely matches. As a result, there is a quicker identification of unknown prints hence enabling fingerprints to be used as widely as they are in criminal investigations. Refrences PEPPER, I. K. (2010). Crime scene investigation: methods and procedures. Maidenhead, Open University Press. Read More