Leaving a Mark: Fingerprint Evidence in Criminalistics
Fingerprints have been known to be one of the oldest and, perhaps, most important types of evidence that can be found used for human identification in criminal investigations. The process for comparing and identifying fingerprints is a long and difficult task that requires multiple individuals with years of training and experience. Understanding the exact definition of fingerprints and how fingerprint evidence is used in criminal investigations is important for anyone who is interested in anything related to criminal justice and criminal law.
As stated before, fingerprints are both unique and specifically individual. According to Cole (2009), “forensic scientists themselves regard the
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uniqueness of material objects (fingerprints) as a fundamental premise whose truth is necessary for forensic analyses to proceed” (p.236). What Cole is stating is that without the uniqueness of fingerprints, there would be no need to analyze and identify them. Three features about fingerprints make their use a means of personal identification: every fingerprint is uniquely individual; throughout a person’s life their fingerprints do not change, unless caused by serious injury or trauma; they are able to be classified for file searching (Gaensslen, Harris, Lee, 2008). What makes fingerprints so unique and individualistic is the friction ridge skin that is found on the fingertips. The soles of the feet and palms of the hands also contain friction ridge skin. The friction ridge skin is made up of complicated patterns of “hills and valleys.” The “hills” are called the ridges and the “valleys” are called the furrows (Gaensslen et al., 2008). The complicated patterns that are found within the friction ridge skin can make up one of three basic fingerprint patterns-arches, loops, and whorls (2008). It is the different variations within these patterns that make up the individualistic characteristics that can only belong to one person and one person only. The fingerprint patterns that a person is born with will stay with them all throughout their lives. The most crucial features when comparing fingerprints are the minutiae. The minutiae are the features that make the pattern in the friction ridge skin individual (Gaensslen et al., 2008). They allow for forensic examiners to compare a fingerprint sample to another known fingerprint sample to determine if it came from the same source. The ridges found on a fingerprint form the minutiae by ending abruptly, splitting into two separate ridges, or sometimes they can even make a dot like shape (Gaensslen et al., 2008). After investigators have recovered fingerprints from a crime scene, the fingerprints can then be classified and stored so that forensic scientists may use them later for identification purposes. Before today’s technologically advanced computer systems, the classification system that was most commonly used to classify and store prints was the 10-print cards. 10-print cards were cards that consisted of an individual’s fingerprints from all five of their fingers from both hands. The subject would place their fingers in an ink pad and then roll them on the card which then left an imprint showing the identifying features and patterns found in the individual’s fingerprint. Forensic examiners would then use these fingerprints to help identify recovered fingerprints from crime scenes. Unfortunately, 10-print cards were not useful for cold-searching for a single print, there had to be a suspect (Gaensslen et al., 2008). Today, automated fingerprint identification systems (AFISs) are being more commonly used to classify and store fingerprints from known subjects. AFISs work the same way as a 10-print card where the subjects five fingers from both hands would be stored; however, these fingerprints are scanned instead of inked. AFISs make storing and identifying fingerprints much easier because the computer systems are able to take known fingerprint samples and pick out other known samples within its storage database that contain identical characteristics. This enables the ability to do cold-searches on fingerprint samples in investigations without a suspect. In order for forensic examiners to view and compare fingerprint samples, the fingerprint evidence must first be developed, collected, and preserved from the crime scene. At times, fingerprints may be found on intact pieces of items that can be collected and carefully packaged as a whole and sent to a laboratory for analysis. Other times, the fingerprints may be found on items that cannot be taken from the crimes scene, so the fingerprint must be well documented and preserved there on the scene. When collecting fingerprints from an item that cannot be moved from the scene the best method would be to first develop the fingerprint and then photograph it. The fingerprint should first be photographed from a distance to show its relation and distance to other objects in the area and then photographed up close to show the minute details for fingerprint comparison (Gaensslen et al., 2008). Not only is it important to collect fingerprints for identification purposes, but as told by Ifa, Manicke, Dill, and Cooks (2008), fingerprints could “potentially contain more forensic information than the simple identification of the subject; they may contain evidence of contact with explosives or substances of abuse (p.805).” Before collecting fingerprint samples, the investigator must first determine which of the three categories of evidentiary fingerprints the samples could be classified under: visible, plastic, or latent prints. Visible prints are fingerprints that do not need any enhancement or development. They are often made from grease, blood, or other visible materials (Gaensslen et al., 2008). Plastic prints are recognizable prints that have been indented into a soft receiving surface like butter or Silly Putty. Latent prints are the most difficult of evidentiary fingerprints because that must be enhanced or developed in order to be collected and preserved. Before doing anything with a latent print, the investigator must first document the object that could potentially contain a possible fingerprint either by photographs, sketches, or both. If the object cannot be collected intact the investigator must then use a latent fingerprint development technique or method to help enhance the fingerprint so that it may be visible. These methods are usually physically or chemically based that target one or more components of latent fingerprint residue (Gaensslen et al., 2008). Powder dusting is considered to be one of the most common physical methods for developing latent fingerprints.
Powder dusting can be observed on many TV shows like CSI and other shows based on criminal investigations. Powder dusting is done by using a type of black or dark in color powder that is collected on a fine brush. The investigator then uses the brush to gently go over any areas that could potentially contain evidentiary fingerprints. The small black powder particles adhere to the fingerprint residue that was left behind which then enhances the details in the fingerprint, making them visible. A magnetic brush may also be used with magnetic particles that also adhere to the residue left by fingerprints. Another procedure that is done to develop latent fingerprints would be to use a small particle reagent. Small particle reagents are usually sprayed or dipped onto an area of an item that is suspected to have fingerprints (Gaensslen et al., 2008). The small particles then adhere to the fingerprint which makes it more visible …show more content…
(2008). There are also many chemicals methods that can be used to develop latent fingerprints. One type of chemical method is iodine fuming. This method involves taking solid iodine and changing it to iodine vapor. The vapor is then deposited onto the ridges of fingerprint pattern which gives the fingerprint residue a visible dirty-brown color (Gaensslen et al., 2008). The use of ninhydrin is one of the oldest methods for developing latent prints using chemical methods. The ninhydrin reacts with the amino acids in the fingerprint residue which gives the fingerprint residue a visible purplish color. Lastly, Super Glue can also be used as a chemical method for developing latent fingerprints. When Super Glue is heated it creates vapors that can be applied to fingerprint residue which reacts and changes the residue into a visible off-white color (Gaensslen et al., 2008). Fingerprint samples, after having been carefully collected and preserved from a crime scene, are then sent directly to a lab where forensic examiners will view and identify the prints.
Fingerprint examiners are very highly skilled individuals who require a lot of experience and training in order to be given the responsibility of making identifications in cases (Gaensslen et al., 2008). As stated before, the use of AFISs has increased greatly for dwindling down the number of possible suspects in a case; however, the final identification is made by a forensic examiner. The first issue before identifying a latent print would be to determine if the print is suitable for examination. The print must have sufficient ridge detail and quality in order for it to be examined and identified. The most common method for examining prints is the ACE-V method which is comprised of four tasks: analysis, comparison, evaluation, and verification. When comparing the samples fingerprints, the comparison is done at multiple levels. The overall pattern and flow of the fingerprint ridges is level I detail (Gaensslen et al., 2008). The minutiae, level II detail, are compared from point to point on the fingerprint (2008). Level III detail involves the size and shape of ridge features and the shape, location, and relationships of the pores (2008). Before 1973, it was determined that a minimum of 12 points that matched between two different fingerprint samples must be made in order to make an acceptable
identification. Now, there is no minimum number of features that is required to make fingerprint identifications. The acceptability of fingerprint identification relies solely on the examiner and their years of training and experience. Fingerprint evidence is one of the most common and oldest types of evidence that is used in criminal investigations. The techniques and methods have even become very well-known in today’s society due to many movies and TV shows about criminal investigations. Although movies and TV shows make identifying fingerprints look easy, the entire process is actually very difficult and requires a lot of highly skilled individuals with years of training and experience. These highly skilled individuals are needed from the beginning of the case when the fingerprints are first collected and developed to when they are sent to labs for further examination and comparison. Without fingerprint evidence, determining the identification of a suspect in a criminal investigation would be a lot more challenging and many criminal cases would be left unsolved.
Other evidence located within the grave consisted of a generic watch, two cigarette butts, a button, a washer and a shell casing. All of these could be analysed for finger prints and DNA. The cigarette butts would also show a serial number indicating the brand (shown in Figure 3), which can be useful if it is found a victim or offender smokes a particular type of cigarette.
The analysis of the samples should be used only to confirm or negate match between the sample taken from the crime scene fgand the sample taken from the suspect. That is, it should sdfremain as an identifgication tool only. There should be no further analysis of the DNA to suggest psychological characteristics that would make the suspect more likely to have cdfommitted the crime. This rule should apply also to samples taken from convicted dfdoffenders for a data vor dagta bank.
Next we will discuss the processes used when dealing with latent prints. First I will discuss the analysis of a latent print. So first when a latent print is sent to the lab who conducts the analysis? The forensic analysis is he person that conducts the analysis, or a fingerprint technician or even a police officer. Bu...
From the early days, with little literary reference material, to the current day, with substantially more, but still insufficient formation, the science of fingerprint identification has managed to maintain its credibility and usefulness. Although, academic institutions have yet to recognize the field as an applied science and include it in the curricula, which would provide directed research and literary reference, in libraries. Without this academic recognition, progress in the field of fingerprint is destined to be sluggish. Description of fingerprint identification as a forensic science’ or an ~app1ied science’ in no way implies that is not a reliable science. Fingerprint identification, correctly understood and applied, is just as scientifically valid and reliable as any other science and, indeed, more accurate than many. The fingerprint expert applies knowledge gained through training and experience to reach a conclusion. The many uses of fingerprint identification range from criminal investigation to non-criminal matters such as deceased, missing persons and disaster victim identification. Fingerprint identification has been used in the court systems for many years. Yet there are those who that still try to challenge fingerprint science and the experts in the court of law by a Daubert Hearing. In this paper, Daubert Hearing is define and detail outing background of the cases, the Government preparation, the Testimony from both sides, the judge’s verdict and finally, Mitchell’s second trial on this case.
Nowadays, DNA is a crucial component of a crime scene investigation, used to both to identify perpetrators from crime scenes and to determine a suspect’s guilt or innocence (Butler, 2005). The method of constructing a distinctive “fingerprint” from an individual’s DNA was first described by Alec Jeffreys in 1985. He discovered regions of repetitions of nucleotides inherent in DNA strands that differed from person to person (now known as variable number of tandem repeats, or VNTRs), and developed a technique to adjust the length variation into a definitive identity marker (Butler, 2005). Since then, DNA fingerprinting has been refined to be an indispensible source of evidence, expanded into multiple methods befitting different types of DNA samples. One of the more controversial practices of DNA forensics is familial DNA searching, which takes partial, rather than exact, matches between crime scene DNA and DNA stored in a public database as possible leads for further examination and information about the suspect. Using familial DNA searching for investigative purposes is a reliable and advantageous method to convict criminals.
Another discrepancy between actual forensics and how it is portrayed in the media is the availability of information in databases. There is only a small percentage of the entire population’s fingerprints or DNA samples stored within databases such as the Integrated Automated Fingerprint Identification System (IAFIS). This makes finding a match between a DNA sample or fingerprint difficult, as a match would only be found if the person’s information was already stored within the database. If there is no match previously stored in a database, the fingerprint or DNA sample could be potentially rendered useless within a trial. Typically, in order to perform an analysis, investigators must already have a suspect in mind and request a DNA or fingerprint sample from him or her. If the suspect does not want to provide one however, the sample collected as evidence may not count as valid. The CSI effect creates an idealized image that all crimes can be solved with a hair or drop of blood, but this is not always the case in real life.
Contextual information also affects the human comparative part of fingerprint analysis, in ways that alter the matching of the same fingerprints, years apart; however, when contextual information is provided, it actually helps 20% of forensic technicians, but that still leaves 80% hindered by contextual information (Dror et al, 2006). Contextual information affects the psychological aspects of perception and problem-solving, in a way that can obscure information that does not support the context, and it can even affect how forensic technician’s view and handle forensic evidence (Bernstein et al, 2013). However, there are some advantages of contextual information, because it can give the forensic division a mental shortcut, saving time and money; however, these shortcuts lead to inaccurate and biased conclusions. This essay has shown that contextual information creates erroneous mistakes and prejudiced results in forensic investigations. A possible way to remove the negative effects of contextual information is to have the forensic technicians, not know the context of the crime so that they do not
By the 19th century, the criminology research scholars have had a keen interest in biometric identification, they hope to combine physical characteristics with criminal tendencies, which resulting in a series of measuring devices, and also collected a large amount of data. Since then, the concept of measuring a person's physical characteristics are finalized, fingerprints also become the identification of international methodological standards for public security agencies. People often debate whether fingerprints have absolutely unique, and also thought that the different countries have the different standard for identifying fingerprints. So far, it is still the most widely methods of public security organs, and the process is also automated.
DNA fingerprinting, or sometimes known as DNA typing, is isolating and developing images of sequences of DNA to evaluate the DNA in an individual’s cells. DNA fingerprinting today is used for many different things in many different areas of science. In forensic science, DNA typing can determine which person did which crime by using blood or skin left at a crime scene. In medical science, patients can find out who their siblings, parents, or children are by using DNA fingerprinting (webmd).
The criminal justice system has changed a lot since the good old days of the Wild West when pretty much anything was legal. Criminals were dealt with in any fashion the law enforcement saw fit. The science of catching criminals has evolved since these days. We are better at catching criminals than ever and we owe this advancement to forensic science. The development of forensic science has given us the important techniques of fingerprinting and DNA analysis. We can use these techniques to catch criminals, prove people's innocence, and keep track of inmates after they have been paroled. There are many different ways of solving crimes using forensic evidence. One of these ways is using blood spatter analysis; this is where the distribution and pattern of bloodstains is studied to find the nature of the event that caused the blood spatter. Many things go into the determination of the cause including: the effects of various types of physical forces on blood, the interaction between blood and the surfaces on which it falls, the location of the person shedding the blood, the location and actions of the assailant, and the movement of them both during the incident. Another common type of forensic evidence is trace evidence. This is commonly recovered from any number of items at a crime scene. These items can include carpet fibers, clothing fibers, or hair found in or around the crime scene. Hairs recovered from crime scenes can be used as an important source of DNA. Examination of material recovered from a victim's or suspect's clothing can allow association to be made between the victim and other people, places, or things involved in the investigation. DNA analysis is the most important part of forensic science. DNA evidence can come in many forms at the crime scene. Some of these forms include hair; bodily fluids recovered at the crime scene or on the victim's body, skin under the victim's fingernails, blood, and many others. This DNA can be the basis of someone's guilt or innocence; it has decided many cases in the twentieth century. As the times continue to change and the criminals get smarter we will always need to find new ways to catch them. Forensic science is the most advanced method yet, but is only the beginning. As the field of science grows so will the abilities of the
Forensic genetics has other applications . The " fingerprint " DNA represents a valuable tool for forensic science . As is the case with an ordinary fingerprint genetic fingerprint is unique to each individual (except identical twins ) . The determination involves the observation of specific DNA sequences which can be obtained from extremely small tissue samples , hair, blood or eventually left at the scene . As Fifty microliters of blood, semen or five microliters of ten roots of hairs are enough , and nozzles secretions and cells from the fetus . In addition to its use in the capture of criminals , especially rapists , the genetic fingerprints can be used to establish family relationships . People involved in the conservation of species use them to be sure that captive breeding is among individuals who do not belong to the same family .
The three different main types of fingerprints are Loops, Arches, and Whorls (Jackson 1). Henry Faulds is known as the Father of Fingerprints and developing fingerprints (Jackson 1). His discovery of fingerprints has made a huge impact not only in his time but, in Modern Crime Scene Investigation (Jackson 1). Without fingerprinting, it would be very difficult to convict criminals of crimes and very hard to try to process information. Crime Scene Investigators make a huge impact in Forensic Science. We need CSI workers, without them people could only imagine what crime would be like not only in our community, but in our
...A. Maria, Ruth M. Robin. (2009). Latent prints: a perspective on the state of the science. Forensic Science Communications. 11.4.
Bloodstain pattern analysis is a forensic discipline that deals with the physics of the blood, and determines the bloodstains left at crime scenes using visual pattern recognition. It is used to shed light on the reconstruction of a crime scene which includes the cause of death starting with homicide, suicide, accident, and identifying areas with high possibility of the offender leaving his or her DNA samples. There are documented descriptions of bloodstain shapes at crime scenes that date back to past centuries, but it was the Samuel Sheppard case in 1955, that prompted advances in this field. Bloodstain pattern analysis is employed worldwide by scientists, police officials and medics in an interdisciplinary manner. Both the blood itself and the surfaces on which the bloodstains are found are important in the assessment of bloodstains. The umbrella organization for bloodstain pattern analysts is the International Association of Bloodstain Pattern Analysts (IABPA), which offers various forms of membership. The name of the method (bloodstain pattern analysis) is often abbreviated to BPA.
In fact, 1 Nano gram or less can produce unexceptional information to find a suspect or a victim of a crime. By means of this technology an investigator can extend their criminal investigation beyond the realms of traditional semen or dried up blood. Crime scenes may consist of less valuable DNA, it subsequently depends on the environmental conditions where the DNA was found. For certain, a sequence of factors ramifies the capability to obtain a pleasing DNA profile. By any means, extended exposure to any type of biological evidence can degrade the DNA, and therefore renders it useless for further analysis.