INTRODUCTION:
A tool mark simply means the impression left by a tool (or a similar object) on any surface when it comes in contact with it. When any tool or an object comes in contact of the surface with a sufficient force to create an indentation, the pattern of the tool gets permanently replicated onto the surface. Examination of tool marks is an important discipline for criminal studies.
The goal of tool mark examination is to establish a link between the tool mark and the tool that was used to create it. Such links are essential in forensic investigations, as the tools are often used in criminal activities, commonly in burglaries, and can actually help to identify a criminal.
For example, if a burglar uses a hammer to break enter into any house, the marks left
A common example is the impression made by a barrel of a gun onto a bullet or by the gun onto a cartridge. These are another category of tool marks. Other examples include the impressions like human or animal bite mark or even the impressions of shoes and tires.
Often the tool mark expert is the person responsible for examining and concluding the expert opinions on such impression's identification.
The examination of tool marks is conducted in different phases. At first the tool mark is observed, measured, and described. Secondly, a photograph perpendicular to the tool mark, is taken. This provides a permanent record of the class and some individual characteristics of the tool mark and also holds a record for the further reconstruction of the crime scene. Then, if the support onto which the tool mark is located cannot be collected as the evidence, a cast of the same is made. This cast is usually made with a polymeric dental paste, plaster of paris,
A body was found with no identification was found on the body. An external examination of the body found numerous needle marks and bruising and thrombosed veins in the cubital fossae. The head showed evidence of a blunt trauma and small paint and metal fragments were removed from the wound. Analysis of the contents in the stomach found a few partially digested potato chips and some partially digested pills. A small amount of residue was extracted from the tin for analysis. Footprints were evident on the carpet where soil had been tracked in. Soil samples were collected from theses footprints. This analysis will show how Infra-red spectroscopy and Chromatography would be useful in finding both the cause of murder and possibly who the culprit was.
285) These types of injuries usually come from knives, axes, or other weapons like that. In some instances, a sharp trauma will look like a line across the bone. So, if someone is not trained in knowing what these marks are, they can be easily over looked. According to Byers (2011) “sharp trauma is the result of narrowly focused, dynamic compression forces applied to the surface of a bone.” (p. 285) Unlike blunt or projectile trauma, sharp force will be focused in a single area, unless the suspect us using an ax or machete there won’t be a large amount destruction to the bones. Using an ax or machete however can severely damage the bones that can look like blunt trauma. So, it is important for the forensic anthropologist to be able to distinguish between them.
SPECIFIC PURPOSE: I want my audience to feel that the partial bite marks are not a reliable way to identify a suspect.
...furniture which may be locked. They then use the small paint chips and metal as evidence and process them the way that individual piece of evidence should be processed.
...ything is on it that it doesn’t wear off and you don’t have it anymore. During this examination you have to tell the size and shape of the bullet. You have to look into the deep things when you doing this because anything can be there just small. (“At The Mortuary”)
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 Art is a sometimes misunderstood and ignored resource for the law enforcement community. Starting with what Forensic Art is defined as, most commonly, it is perceived as any art that can or is used in law enforcement or legal proceedings. This field has several recognized skill sets most prevalent of which are demonstrative evidence, crime scene/composite sketches, image modification/ identification, and postmortem or facial reconstruction. Having a history stretching back to the 1800s forensic art has grown and improved over the course of the following years. First giving a brief history on where forensic art started and then following with some of the benefits each skill set of forensic art provides to the law enforcement community. I will try to show the progression of forensic art and how it can be used by modern law enforcement.
Review, PubMed PMID: 19543886. Saferstein, R. (2011). Criminalistics: An introduction to forensic science (10th Ed.). Upper Saddle River, NJ: Pearson Education, Inc.
Fingerprints are collected from the evidence, and ran through a database such as IAFIS. DNA evidence that is extracted from hair, bodily fluids and skin cells are also ran through databases that help identify the suspects. Firearms, bullets and cartridges are analyzed and can be used to trace a weapon back to its owner. All of the information gathered from collected evidence is pooled together to create a solid base for use in the conviction of suspects in a crime.
More complex tools, such as DNA analysis kits, stereo zoom microscopes, or optometric boards for measuring bones, are specific to the kind of anthropology being studied. It is important when going into a field that anthropologists coming from more “modern” societies do not brandish certain tools that can alarm the population they are studying (such as using flash photography among indigenous people, who have never seen a camera before.) This can create distrust between the indigenous people and the anthropologists and endanger the welfare of both parties.
Certain heads, certain colors and textures of human hair leave permanent marks on me. Other things too. Charlotte once ran away from me outside the studio and I grabbed her dress to stop her, to keep her near me. A yellow cotton dress I loved because it was too long for her. I still have a lemon-yellow mark on the palm of my right hand, I'm a kind of paranoiac in reverse. I suspect people of plotting to make me happy. (Salinger Raise 75-76)
Gaensslen, R. E., Harris, H A., & Lee, H. (2008). Introduction to Forensic Science and Criminalistics. New York, NY: The McGraw-Hill Companies, Inc. .
Forensic Science, recognized as Forensics, is the solicitation of science to law to understand evidences for crime investigation. Forensic scientists are investigators that collect evidences at the crime scene and analyse it uses technology to reveal scientific evidence in a range of fields. Physical evidence are included things that can be seen, whether with the naked eye or through the use of magnification or other analytical tools. Some of this evidence is categorized as impression evidence2.In this report I’ll determine the areas of forensic science that are relevant to particular investigation and setting out in what method the forensic science procedures I have recognized that would be useful for the particular crime scene.
...ot be found, the forensic dentists uses a post-mortem dental profiling to aide in narrowing down the search (3). Bite marks are quite common in forensic odontology. The American Board of Forensic Odontology has broken up bite mark analysis into 3 major stages. These stages are a description of bite marks, the collection of evidence from the victim and the suspect and finally, the analysis of the bite marks (5). The methods used to perform this task are the manual process which using tracing, photocopier generated overlays, 2D polyline method and the painting method (4). Despite having better and more improved methods to conduct the comparison of bite marks, there still exists a huge problem. The problem involves the physical properties of skin which may cause the bite mark to change (5). Hopefully, in the future more research is done to overcome this issue.
When a suspect’s weapon is examined in the lab, it will be test fired into a box filled with cotton or a tank of water to provide the examiner with the bullets and cartridges with a known history. Using a microscope, the known cartridges are compared with the ones in question. With some patience, skill, and a little luck, experts can definitively say that a certain firearm and no other fired this bullet, or ejected this cartridge.