Forensics in Criminal Investigations Exploring the Use of Forensics in Criminal Investigations

Forensic Science and Technology

This paper explores the role of forensic science and technology in modern criminal investigations. It first examines the nature and role of physical evidence in regards to how it is uncovered, preserved, and analyzed within forensics today. Physical evidence is described in the varying types and categories. Then, the paper moves to evaluating different types of forensic sciences. This evaluation includes pattern evidence, like fingerprinting, tire and foot prints, as well as firearm pattern evidence like ballistics. DNA forensics and techniques are then discussed, as this is one of the most recent and widely accepted forensic methods used in today's investigations. Then, the paper discusses anatomical forensics, including the modern use of entomology in order to help determine the time of death in murder investigations. Finally computer forensics are explored, as crimes are not always physical in nature but can be proven with evidence taken from computers and viral technology. All of these types of forensics are crucial to modern investigations and play a role in criminal investigations today.

Criminal investigations have come a long way since the inception of law enforcement in modern society. Part of this rapid evolution has been the increasing complexity of forensic science and analysis as used within the context of criminal investigations. Forensics helps criminal investigations uncover, process, and analyze data relating to certain crimes being investigated. These can be violent or physical crimes, such as a murder, or they can be financial and electronic in nature. A With such a varied degree of crimes being committed in the world today, the use of forensics within law enforcement and criminal investigations is quite multi-faceted and includes a number of sub-fields depending on the nature of each individual crime and circumstance.

Forensics relies on the uncovering, preservation, and analysis of physical and digital evidence. In criminal investigations, evidence is crucial in order to prove theories of criminal events occurred and to prove a suspect's involvement with particular crimes.

Evidence "can take any form. It can be as large as a house or as small as a fiber. It can be as fleeting as an odor or as obvious as the destructive results at the scene of an explosion" (Fisher & Fisher, 2012, p 1). It is incredibly varied in regards to what constitutes as reliable evidence. The nature of the evidence really depends on the crime, and thus forensics must be flexible enough to be able to collect and analyze evidence in its wide variety of forms. According to the research, "physical evidence can prove a crime has been committed or establish key elements of a crime" (Fisher & Fisher, 2012, p 1). Forensics helps work to classify the source of evidence so that it can be interpreted by lawn enforcement in its relation to the crime in question. Forensics additionally works to collect and preserve evidence so that it can be used later in a court of law. Once evidence is found at the scene of a crime or elsewhere, it must be meticulously categorized, labeled, and stored for later analysis. Any exposure to external stimuli may potentially compromise the legitimacy and the worth of the evidence in question. Once evidence has been collected, it is up to forensic scientists and other specialists to make educated assumptions and conclusions regarding the nature of the evidence. Then, "specially trained personnel -- forensic scientists, criminalists, forensic technicians, or identification technicians -- examine physical evidence collected at crime scenes. These specialists prepare reports and testify in court as expert witnesses" (Fisher & Fisher, 2012, p 14). Forensics, as a field, encompasses the collection and analysis of all types of evidence.

One of the oldest and most trusted forensic methods is fingerprinting. The human finger has a completely unique print for each individual and patterns of prints left behind at crime scenes can be very convincing evidence in a court of law. Prints can be uncovered through dusting with a special type of powder that exposes oils from the hand and fingers. Forensic investigators use cellophane tape or printing ink to copy finger prints found at the scene for later analysis. Once these prints are collected, they can be scanned into a computer and run through an Automated Fingerprint Identification System, which have "revolutionized the way police departments search for latent prints for matches" (Fisher & Fisher, 2012, p 117). These are nation-wide databases that hold records of individuals fingerprinted...

Previously, law enforcement officials had to manually look through printed catalogues, which took significantly longer than the highly specialized computer generated searches that now take mere minutes to complete. Forensic scientists look to match patterns to prints left at various crime scenes in order to identify any potential suspects that may have been present at the scene when the crime took place. The highly accurate print mapping programs also help forensic scientists to distinguish more characteristics in partial or damaged prints let at the scene, making investigation processes run much smoother. Similar techniques are also used for palm and foot prints.
Other types of pattern evidence can also be collected through using forensics. Tire marks, show impressions, tool marks, and other physical markers can be uncovered through forensic investigations and then preserved and analyzed using forensic science. Foot prints and tire marks are most often found outside and so it is important for forensic teams to preserve and copy the evidence as quickly as possible so evidence is not destroyed by weather and the elements. Such marks are often preserved through the use of casting and photography, which can then later be analyzed using computer software and geometric elements. The main purpose of such collection and analyzing pattern evidence is to be able to link a specific pattern to an object that is connected to a victim or suspect. This will help strengthen a connection that could result in a conclusion of the crime.

In the case of violent offenses, like attacks and murders, finding and analyzing the weapon used is a crucial goal of forensics in order to aid in the criminal investigation of the incident. In shooting cases involving fire arms, forensic specialists work with ballistic evidence to match fire arms to shell casings and bullets left at the scene. According to the research, "ballistics and the trajectory of projectiles recovered will be of importance" in helping paint the picture of how the violent incident occurred reliably enough to stand in a court of law (Douglass & Burgess, 2011, p 142). Ballistics refers to the markings or riffling that is left on bullets and shell casings. These markings are unique to each firearm and can thus be used to show what particular weapon was used in certain crimes. If the markings on a shell casing left at the scene match the markings seen in a weapon found in a suspect's home or possession, this is a strong connection that can hold up in a court of law. However, "customized suppressors, handguns, or other instruments" meant to stifle sounds or tamper with riffling marks can make analysis of ballistic evidence difficult and requires a multi-faceted forensic approach that uses combinations of different analytical techniques (Douglass & Burgess, 2011, p 134). Thus, modern forensics aims to not only be able to identify markings but also increase the likelihood that markings can still be identifiable in the event some sort of suppression mechanism has been used.

Additionally, DNA analysis is a crucial part of modern forensic science. The research states that "since 1985 DNA typing of biological material has become one of the most powerful tools for personal identification in forensic medicine and criminal investigations" (Benecke, 1997, p 181). DNA is incredibly reliable and since the inception of DNA analysis, forensics has become a much more powerful force in regards to its ability to identify suspects and victims, even years after a crime has occurred. DNA analysis is essentially like "genetic fingerprinting" (Benecke, 1997, p 181). Each individual has a unique genetic make up, just like their fingerprints. DNA analysis focuses on exposing and then identifying such genetic markers so that they can be linked to a suspect or victim using comparison or matching from a national database. The process is incredibly complex and is continuing to become more and more reliable as new technologies are introduced. According to the research, "DNA testing uses the statistical occurrence of discrete pieces of genetic material or alleles. These alleles have different frequency values developed from population databases" (Fisher & Fisher, 2012, p 7). From biological material, DNA patterns and pattern fragments can be lifted and then used to determine identification. Due to the fact that DNA is so specific in regards to it being a marker for individual identity, it is highly reliable, with nearly a 99% probability of accuracy in regards to identification. The following chart examines how DNA can be lifted from stains:

(Benecke, 1997, p 182)

DNA is used to determine identity and can be gathered from…