Introduction
When analyzing physical evidence, there are many different approaches available for forensic analysis. However, it should be noted that no single method or technique yields satisfactory results. Often, the item of forensic interest may require the use of multiple instruments. There is a growing need for advancement for new forensic tools, one that will optimize analytical figures of merit along with many other principal factors such as cost efficiency (cost per analysis), ease of use, instrumentation portability, time for sample preparation, sample consumption, and throughput [5]. In a typical crime scene, analysts analyze numerous trace evidence samples that require determination of their elemental composition. However,
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It has been successfully applied to the elemental analysis of various materials, including those of forensic interests [5]. Its growing attraction is due to its high sensitivity, rapid results, and virtually micro-destructive features, just to name a few. Its versatility and low-cost adaptation of atomic emission spectroscopy, has been utilized effectively to the forensic analysis of counterfeit currency, drugs, explosives, fingerprints, ink and paper, glass, gunshot residue, and many other items of specific forensic interests. The method requires little to no sample preparation and can simultaneously provide information on major, minor and trace element compositions [5]. LIBS also has the potential to be used in real time on the field for direct or stand-off analysis. The instrumentation needed is reasonably simple, very robust, and is also available in a compact format the enables portable …show more content…
The plasma consists of electronically excited atoms and ions, which can then be analyzed by the spectrometer. When the laser pulse terminates, the plasma begins to cool [11]. It is during this cooling process, where the electrons of the atoms and ions at the excited states decay back into their natural ground states, causing the plasma to emit characteristic wavelengths of light. The atomic emissions can be detected approximately 1 μs after the initial pulse. The emitted light from the plasma is collected by the spectrometer coupled with either a CCD or ICCD spectrograph detector module for the LIBS spectral analysis [11]. Each element correlates to a unique LIBS spectral peaks. Thus, by identifying the different peaks of the analyzed sample, its chemical composition can be rapidly
Forensic Science Introduction: Someone in a restaurant has suddenly fallen ill and a mystery powder has been discovered with the victim. As the chief investigator, your duty is to identify the mystery substance through a lab. In this lab, it will consist of five known compounds and one unknown compound. Your job is to distinguish which one out of the five substances is the mystery powder. To figure out the mystery matter you will have to compare their physical and chemical properties and match them with the appropriate compound.
This specific lab will focus on the two main variants of Atomic Absorption Spectroscopy: flame AA spectroscopy, and spectroscopy using a graphite furnace. The lab will also introduce and teach how to deal with both systematic and random error when using Atomic Absorption Spectroscopy.
Crime scenes are known to have many clues left behind. The obvious would be a the body or bodies, clothing, and sometimes even the murder weapon. While these are great way to solve a case there's another kind of evidence; trace evidence. Trace evidence are small pieces of evidence that are laying around a crime scene. There are many types of trace evidence some of them include metal filings, plastic fragments, gunshot residue, glass fragments, feathers, food stains, building materials, lubricants, fingernail scrapings, pollens and spores, cosmetics, chemicals, paper fibers and sawdust, human and animal hairs, plant and vegetable fibers, blood and other body fluids, asphalt or tar, vegetable fats and oils, dusts and other airborne particles, insulation, textile fibers, soot, soils and mineral grains, and explosive residues. Although these are the most common found elements, they are not the only ones. The Trace Evidence Unit is known to examine the largest variety of evidence types and used the biggest range of analytical methods of any unit. materials are compared with standards or knowns samples to determine whether or not they share any common characteristics. In this paper I will discuss the different kinds of trace evidence and how crime scene investigaros use it to solve cases and convict criminal.
Therefore, the criminal justice system relies on other nonscientific means that are not accepted or clear. Many of forensic methods have implemented in research when looking for evidence, but the methods that are not scientific and have little or anything to do with science. The result of false evidence by other means leads to false testimony by a forensic analyst. Another issue with forensic errors is that it is a challenge to find a defense expert (Giannelli, 2011). Defense experts are required to help the defense attorneys defend and breakdown all of the doubts in the prosecutors scientific findings in criminal cases. Scientific information is integral in a criminal prosecution, and a defense attorney needs to have an expert to assist he/she in discrediting the prosecution (Giannelli,
“Advance in Forensics Provide Creative Tools for Solving Crimes.” www.ctcase.org. Np. n.d. Web. 17 March 2014.
Forensic toxicology is one of the oldest disciplines in forensic science history and dates back hundreds of years. However, the actual understanding and examination of forensic toxicology only dates back for about 200 years. Due to the development of technology, this discipline has been able to progress and flourish. The term forensic toxicology is defined as examination of all aspects of toxicity that may have legal implications (James & Nordby, 2009 p. 61).
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
In today’s time, modern Crime Scene Investigation has increased rapidly. From throughout the late 1900’s and in the early 2000’s (Taylor 1). For all of the evidence that they find, a solid foundation has formed over the thousands of years of Crime Scene
The following information will focus on the two substances forensic scientist use to identify and compare matter, whether a material is organic or inorganic. Evidence that will be used in a court trial will depend on the examination that forensic scientist processed in the laboratory. The importance of distinguishing between organic and inorganic material is a necessary step in the criminal justice process. The differences between organic and inorganic will be explained first, next will be to explain the strengths and weaknesses of each, and finally the significance of both as it relates to the justice system. Also, we will focus on soil as it relates to how specific evidence is used in each instance. Now let’s begin by listing the differences.
White, P 1992, Crime scene to court: the essentials of forensic science, Royal Society of Chemistry, London, p. 20-33.
Each scientist or team of scientists had so much trouble reducing the Lithium compounds because Lithium does not exist in its elemental form in nature. It combines very easily with other elements. Lithium is a soft silvery-white lustrous metal, which can be easily cut with a knife, and it is the lightest of all known metals. It is highly reactive with water and air, and tarnishes readily when exposed to the latter due to a formation of a layer of Lithium suboxide on its surface. Because of its high rate of reaction to air, it must be stored under liquid paraffin, oil, or kerosene, which contain no air, to prevent oxidation. Lithium is detected in its compounds by the characteristic red coloration that it imparts to flames when burned, as Gmelin detected, and by spectroscopic methods.
Spectroscopy Spectroscopy is the study of energy levels in atoms or molecules, using absorbed or emitted electromagnetic radiation. There are many categories of spectroscopy eg. Atomic and infrared spectroscopy, which have numerous uses and are essential in the world of science. When investigating spectroscopy four parameters have to be considered; spectral range, spectral bandwidth, spectral sampling and signal-to-noise ratio, as they describe the capability of a spectrometer. In the world of spectroscopy there are many employment and educational opportunities as the interest in spectroscopy and related products is increasing.
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.
Forensic science has now been recognized as an important part of the law enforcement team to help solve crimes and cold cases. The advances in technology are being used each day and we must continue to strive to develop better advances in this field. The recent discovery of using DNA in criminal cases has helped not only positively identify the suspect, but it has helped exonerate hundreds of innocent individuals. “With new advances in police technology and computer science, crime scene investigation and forensic science will only become more precise as we head into the future.” (Roufa, 2017) Forensic science and evidence helps law enforcement officials solve crimes through the collection, preservation and analysis of evidence. By having a mobile crime laboratory, the scene gets processed quicker and more efficiently. Forensic science will only grow in the future to be a benefit for the criminal justice
Physical evidence is additionally important in every criminal investigation because too often witness accounts are sometimes biased or unreliable. Physical evidence such as trace evidence, DNA, and fingerprints may objectively attach one or more persons to a victim or suspect to a crime. Favorably, physical evidence can also demonstrate inestimable for exonerating an innocent suspect. Laboratory members and criminal investigators should perform together to resolve the biggest portion of evidence to institute the right suspect for a strong prosecution. Willingly, investigation officers should aggressively contact laboratory personnel when questions arise about the cases because DNA evidence is sensitive.