Forensic laboratory
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The document provides an overview of a forensic laboratory, including its various departments and the analytical techniques used. It discusses the biology/DNA lab which examines blood, fluids, and tissues and performs DNA sequencing. The chemistry lab tests for drugs, poisons, and chemicals using techniques like GC/MS and HPLC. Other labs discussed include trace evidence, firearms, photography, and materials analysis. The document outlines the instruments used such as FTIR, GC/MS, LC/MS, microscopes, and describes some common analytical methods in forensic science.
Forensic laboratory
- 2. 2 ForensicLaboratory To everyone who has helped us with support, new books, hard/soft ware And over the internet Special thanks for Thermo http://www.thermofisher.com
- 3. 3 ForensicLaboratory • Introduction • Lab. Departments • Lab. Design • Main Instruments
- 5. 5 ForensicLaboratory • The word forensic comes from the Latin adjective forensis, meaning "of or before the forum." In Roman times, a criminal charge meant presenting the case before a group of public individuals in the forum. • The term "forensic" is effectively a synonym for "legal" or "related to courts".
- 6. 6 ForensicLaboratory In Some classification the laboratory was divided into four main areas of investigation: • Biology • Chemistry • DNA • Drugs / Toxicology
- 7. 7 ForensicLaboratory Other classification, The laboratory is divided into many areas of investigation: • Fingerprint lab. • Trace evidence lab. • Serology / DNA labs. • Materials lab. • Firearms lab. • Photography lab. • Chemistry lab. • Others labs
- 9. 9 ForensicLaboratory The items to be tested for fingerprints, • A newspaper, • A glass bottle, • A floppy disk, and • A glossy magazine.
- 10. 10 ForensicLaboratory • Skin is generally divided in to two layers. • These are the inner layer (dermis) and the outer layer (epidermis). • The outer layer is divided into five stratified sub-layers, which are listed from bottom to top as, • Basal generating layer • Spinous layer • Granular layer • Transitional hyaline layer • Horny cornified layer.
- 11. 11 ForensicLaboratory Fingerprint Detection Techniques: 1. Iodine Fuming 2. Superglue Fuming 3. Powders 4. Ninhydrin Spraying
- 12. 12 ForensicLaboratory • A dedicated workstation for the recording and enhancement of latent fingerprints • An optical projector for the visual comparison of record and recovered fingerprints Some technique’s
- 13. 13 ForensicLaboratory In most labs, a unit commonly known as a 'trace evidence unit' forms an area where scientists look for clues in evidence such as: • Hair, • Fabric, • Dust, • Fiber and • Skeletal remains. • Refer to the “Every Criminal Leaves A Trace”.
- 14. 14 ForensicLaboratory • Recovering, comparing and identifying non-biological trace evidence • Paint, • Potential fire accelerants, • Glass, fibers and textiles, • Plastics, building products, • Safe insulation and commercial products; • Conducting physical matching of the seized materials; • Providing scientific and technical support to other forensic disciplines; and hosting and supporting the Paint Data Query (PDQ) database.
- 15. 15 ForensicLaboratory • Multi-functional forensic trace evidence analysis system • Trace evidence elemental analysis by laser induced breakdown spectroscopy - LIBS Some technique’s
- 16. 16 ForensicLaboratory Forensic serologists: scientists who examine physical evidence with the intent of finding, identifying and individualizing stains of biological origin. The serology unit specializes in the identification and analysis of:- • Bloodstains, • Bodily fluids, • DNA sequencing. The most common of the DNA tests, the polymers chain reaction( PCR), is now able to be performed in small laboratories,
- 17. 17 ForensicLaboratory Bloodstain analysis traditionally follows the following steps: • Is the stain blood? • Is the stain animal or human blood? • If human blood, what type? • Can the sex, age, and race of the source of blood be determined?
- 18. 18 ForensicLaboratory • Tiny particles of blood will cling to most surfaces for years • Hidden blood spatter patterns can help investigators locate the point of attack and even what sort of weapon was used (a bullet makes blood splatter very differently than a knife does). • Luminal may also reveal faint bloody shoe prints, which gives investigators valuable information about the assailant and what he or she did after the attack
- 19. 19 ForensicLaboratory • Forensic DNA analysis deals with the identification of the source of a body fluid through DNA testing two samples are taken, one from the suspect and one from the scene of the crime. • The samples can be skin tissue, hair, blood, semen or vaginal fluid, and really anything else with cells in it (the two samples don’t even have to be the same material because all cells of the same organism have identical DNA). • Then, the DNA of both samples is extracted, studied, and compared. If the DNA matches, then the suspect was at the scene of the crime.
- 20. 20 ForensicLaboratory • Identify potential suspects whose DNA may match evidence left at crime scenes. • Exonerate persons wrongly accused of crimes. • Identify crime and catastrophe victims. • Establish paternity and other family relationships. • Identify endangered and protected species as an aid to wildlife officials (could be used for prosecuting poachers). • Detect bacteria and other organisms that may pollute air, water, soil, and food. • Match organ donors with recipients in transplant programs. • Determine pedigree for seed or livestock breeds. • Authenticate consumables such as caviar and wine.
- 21. 21 ForensicLaboratory Material units are used to identify and analyze :- • Metals, • Paints, • Ceramics, • Soil, • Wood. In an attempt to trace a crime back to a possible suspect. The biology unit is in charge of analyzing all biological evidence such a seeds and plants.
- 22. 22 ForensicLaboratory • Firearms units test weapons to see which weapon made the mark on an object or wounded or killed a person. • To be able to carry out these tests, firearms specialists study the used bullet cartridges and use shooting baths to fire weapons, identify the bullet marks and establish the firing distance.
- 23. 23 ForensicLaboratory Firearms can be test-fired to obtain known specimens for comparison with evidence ammunition components, such as:- • Bullets, • Cartridge cases, • Shot Pellets, Buckshot, or Slugs, • Wadding, • Unfired Cartridges or Shot shells, • Gun Parts, • and shot shell casings.
- 24. 24 ForensicLaboratory • Photography plays a vital role in the forensic laboratory, as photography is used to document crime scene evidence. • Processing resources and dark room services allow specialists in the area of photography to analyze photographs and bring the evidence to light.
- 25. 25 ForensicLaboratory • Physical dimensions can be derived from images through the use of geometric formulas or on-site comparison. • For on-site comparisons, examiners enter the scene and place a height chart at the location of the subject(s) or object(s) of interest. • Examples of Photogrammetry include determining the height of a bank robbery subject(s) and the length of the weapon (s) used by the subject(s) depicted in surveillance images.
- 26. 26 ForensicLaboratory Photographic evidence—including • Film, • Video, • Digital images, and • Prints. can be examined to determine whether the image is the result of a composite, an alteration, or a copy.
- 27. 27 ForensicLaboratory • Large labs also have arson and explosives experts as well as specialists in software, computer data, files, documents, audios and video recordings. • The units available in different labs will vary from one to the other, however, the need for certain analyses and the budget of each lab determines the availability of the departments.
- 28. 28 ForensicLaboratory A chemistry unit is present in any laboratory and is used to test samples of:- • Blood and urine for alcohol, • Drugs and poisoning. • Synthetic materials such medicines, • Dyes and stains. Specialists in the area of chemistry also rely on FTIR, gas chromatographs, mass spectrometers, atomic absorption and microscopes to identify chemicals.
- 30. 30 ForensicLaboratory Main……. 1. Building. 2. Utility. 3. Furniture. 4. Tested Samples. 5. Methods of analysis 6. Instruments. 7. Chemicals. 8. Glass ware. 9. Staff.
- 31. 31 ForensicLaboratory Building Design Issues • Safety. • Walls painting. • Electrical plugs. • Flooring. • Partitions. • Exhausting and ventilation systems. • Fire fitting system.
- 32. 32 ForensicLaboratory Utility Services: • Utility connections in Laboratory space types can include vacuum, • Pneumatic supply, • Natural gas, O2 and CO2, • Required cylinder, • And distilled water. The fittings and connections for each module.
- 33. 33 ForensicLaboratory • Design the furniture's. • Design depending on the available spaces. • Isolation of preparation area. • Size of instruments. • Sequence of test methods. • Safety regulations. • Prevent interference bet. Labs.
- 34. 34 ForensicLaboratory Two main classes of chemical compounds, Organic compounds • Are based on carbon and are found in living things. Inorganic compounds • Are those based on other elements. • From the point of view of forensic science, both organic and inorganic compounds are found in items of evidence. • The techniques used for determination of chemical composition of such evidence often depend upon whether the component compounds are organic (derived form living tissue or material) or inorganic.
- 35. 35 ForensicLaboratory Biological samples include: • Blood, • Urine, • Hair, • Nails, • Saliva, • Tissues and • Exhaled breath. Non-biological samples include: • Unidentified pills, • Powders, • Liquids, • Gases.
- 36. 36 ForensicLaboratory Broad classes of substances frequently found in post-mortem investigations Gases and volatiles Acids Neutrals Bases Metals Alcohols, chlorinated hydrocarbons, aromatic hydrocarbons, carbon monoxide, cyanide Barbiturates, salicylates, paracetamol (acetaminophen) Glutethimide, ethchlorvynol, meprobamate, carisoprodol Cocaine, propoxyphene, opium alkaloids, antidepressants, benzodiazepines Heavy metals
- 37. 37 ForensicLaboratory Type Quantity Analysis Blood (heart, femoral) 20 ml Volatiles, drugs Urine 20 ml Drugs, heavy metals Bile 20 ml Narcotics, other drugs Kidney Entire In absence of urine Liver 20 g Many drugs Gastric contents Total Drugs taken orally Vitreous humor Both eyes Alcohol, glucose, drugs and electrolytes
- 38. 38 ForensicLaboratory Pathological observation Possible cause Burns around mouth, lips, nose Acids Skin of face and neck quite dark Aniline, nitrobenzene Severe, unexplained diarrhea Metals (arsenic, mercury, copper, etc.) Pupil of eye dilated Atropine (Belladonna), Scopolamine Burns around mouth, lips, nose Bases (lye, potash, hydroxides) Odor of disinfectant Carbolic acid or other phenol Skin is bright cherry red Carbon monoxide Quick death, red skin, odor of peach Cyanide Vomiting, abdominal pain Food poisoning Diarrhea, vomiting, abdominal pain Metallic compounds Convulsion Nicotine Odor of garlic Oxalic acid, phosphorous Convulsion Sodium fluoride
- 39. 39 ForensicLaboratory • All methods are standard methods. • The selected methods will be suitable for Lab samples. • Reference for all methods. • QC applications for Methods of analysis.
- 40. 40 ForensicLaboratory All the required instruments chosen according to: • Test methods. • Up to date version. • Good reputation instrument manufactures. • Technical Comparisons results between suppliers.
- 41. 41 ForensicLaboratory • There are thousands of possible substances that could be encountered in poisoning or drug overdose cases and millions of possible substances that could be found in non-biological samples. • There are techniques for the analysis of almost all of these, but without a short list of possible agents it would be a very difficult task to decide what to look for and what technique to use.
- 42. 42 ForensicLaboratory • Some of the more common analytical techniques used in forensic toxicology Compound Sample nature Method Gases & Volatile Compounds Simple mixtures, known compounds GC " Complex mixtures, unknown compounds GC / MS Non-volatile organic compounds Simple mixtures, known compounds HPLC " Complex mixtures, unknown compounds LC / MS Toxic Metals AAS / ICP
- 44. 44 ForensicLaboratory All the required instruments chosen according to test methods: 1. FTIR. 2. GC/MC. 3. LC/MS 4. HPLC 5. Microscope. 6. Atomic Absorption. 7. ICP – ICP/MS 8. Others instruments.
- 45. 45 ForensicLaboratory • FTIR Spectroscopy is a molecular spectroscopy which is used to characterize both organic and inorganic evidence. • The sample is bombarded with infrared radiation. • When the frequency of the infrared radiation matches the natural frequency of the bond, the amplitude of the vibration increases, and the infrared is absorbed. • The output of an infrared spectrophotometer is a charts.
- 47. 47 ForensicLaboratory Transmission Reflectance
- 49. 49 ForensicLaboratory FTIR is a valuable forensic technique because of its detection sensitivity and versatility. Chemicals from a variety of sample types including : • Blood, • Paints, • Polymer coatings, • Drugs and • Both organic and inorganic contaminants can be identified
- 50. 50 ForensicLaboratory The GC/MS is comprised of two parts: • The gas chromatograph / the mass spectrometer. • The gas chromatograph functions by separating the molecules within the sample compound into their most elemental particles, allowing some types of molecules to pass into the mass spectrometer more rapidly than others. • When the molecules move into the mass spectrometer, they are broken down into ionized fragments, and then each molecule is specifically identified based on mass and ionic charge.
- 51. 51 ForensicLaboratory • The mass spectrum for 2,6- dimethylaniline is shown below the chromatogram as an example. • Peaks in the mass spectrum are representative of fragments from the parent compound induced by the instrument during detection. • Every compound gives a unique mass spectrum, thus allowing for structural assignments to be made.
- 53. 53 ForensicLaboratory 1. A small sample of compound is ionized, usually to cations by loss of an electron. 2. The ions are sorted and separated according to their mass and charge. 3. The Mass Analyzer to separated ions are then detected and tallied, and the results are displayed on a chart. 4. The Detector
- 54. 54 ForensicLaboratory Forensic applications of GC/MS include identification and detection of :- • Explosives, • Investigations of arson, • Fire, and blasts or explosions, • Environmental analysis, • And drug detection.
- 55. 55 ForensicLaboratory • In LC–MS, there has been an explosion in the range of new products available for solving many analytical problems, particularly those applications in which non-volatile, labile and/or high molecular weight compounds are being analyzed.
- 56. 56 ForensicLaboratory • LC–MS is a well-established technique for explosives in associated complex matrices such as post-blast residues and in environmental samples such as soil and plant material extracts. • LC–MS to enable unambiguous differentiation • between structurally related textile dyes which were previously indistinguishable by UV–VIS absorption profile or by micro spectrophotometry.
- 57. 57 ForensicLaboratory • High-performance liquid chromatography (HPLC; formerly referred to as high-pressure liquid chromatography), • Is a form of liquid chromatography where the high pressure used to separate the mixture components, then identify, and quantify
- 58. 58 ForensicLaboratory HPLC instruments consist of: 1. Solvent rack, 2. Pump, 3. Injector, 4. Separation column, 5. Detector.
- 59. 59 ForensicLaboratory Some of the most popular applications to evidence analysis are:- • Drugs • Soils • Inks • Explosives
- 60. 60 ForensicLaboratory • Visible microspectrophotometry is a very useful tool in the forensic analysis of many kinds of trace evidence. • It combines a microscope with a spectrophotometer so that the light absorption properties of a very small sample can be recorded.
- 61. 61 ForensicLaboratory The technique is particularly valuable in the investigation of:- • Hair, • Textile fibers, • Paint, • Colored inks which are typically of microscopic dimensions. A fiber, for instance, may have a diameter of only around 20 micrometers.
- 62. 62 ForensicLaboratory • A technique for determining the concentration of a particular metal element in a sample. • The technique can be used to analyze the concentration of over 70 different metals in the prepared solution.
- 63. 63 ForensicLaboratory • Lamp • Atomizer • Monochromator • Photomultiplier tube • Optical system • Automatic gas control
- 64. 64 ForensicLaboratory • Qualitative Analysis of an Inorganic Compound • A poison is a substance that can cause, to an organism, injury, illness or death when a sufficient quantity is present. • This indicates that any chemical substance in sufficient quantities can act as a poison even table salt.
- 65. 65 ForensicLaboratory • There are 35 metals that concern us because of occupational or residential exposure; 23 of these are the heavy elements. • Or "heavy metals": antimony, arsenic, bismuth, cadmium, cerium, chromium, cobalt, copper, gallium, gold, iron, lead, manganese, mercury, nickel, platinum, silver, tellurium, thallium, tin, uranium, vanadium, and zinc . • Interestingly, small amounts of these elements are common in our environment and diet and are actually necessary for good health, but large amounts of any of them may cause acute or chronic toxicity (poisoning).
- 66. 66 ForensicLaboratory Forensic and clinical applications • Blood, urine, serum, tissue, bone and hair, Al, Cr, Cu, Zn, As, Se, Cd, Pb, Hg • Some elements toxic Al, As, Cd, Hg, Pb • Some essential Se, Fe, Zn, Cr • Some vital at low levels, toxic if high Cu, Zn, Se
- 67. 67 ForensicLaboratory Inductively Coupled Plasma – Atomic Emission Spectroscopy (ICP-AES), • It is a multi-element analysis technique that will dissociate a sample into its constituent atoms and ions and exciting them to a higher energy level. • Cause them to emit light at a characteristic wavelength , which will be analyzing
- 68. 68 ForensicLaboratory Steps • Plasma will dissociate a sample into atoms , ions. • Exciting them to a higher energy level. • Atoms and ions emits light at a characteristic wavelength . • The emitted light, will be analyzing . The instrument will know the concentration of metals inside the sample, using standard solutions.
- 69. 69 ForensicLaboratory The iCAP 7000 spectrometer consists of several major components: • Sample introduction parts. Plasma torch. • Gas control. • Radio frequency power generator. • Optical system; Polychromator. • CID detector with thermoelectric cooling. • Interlocks.
- 70. 70 ForensicLaboratory • Environmental Analyses Applications • Petrochemical Analyses • Metallurgical analyses • Geological analyses • Foodstuffs analyses • Forensic applications.
- 71. 71 ForensicLaboratory • UV-VIS spectroscopy . • Polarizing light microscopy. • Atomic Force Microscopy (AFM). • X-Ray Photoelectron Spectroscopy (XPS). • Thin layer chromatography . • Scanning Electron Microscope (SEM). • Polymerase chain reaction PCR.
- 72. 72 ForensicLaboratory • All chemicals prepared according to the stander methods of analysis. • The purity of required chemicals. • Quantities of chemicals per one year. • MSDS for all chemicals. • Hazardous notes about all chemicals. • Quantities of chemicals per one year.
- 73. 73 ForensicLaboratory • All Glass ware prepared according to the stander methods of analysis. • The grid of required glass wares. • Amounts of glass wares. • Storage requirements for items.
- 74. 74 ForensicLaboratory The training of all staff on: • SOP’s • Selected instruments. • Methods of analysis. • Sampling. • Preparation of samples. • QC of the tests.
- 75. 75 ForensicLaboratory The specific questions that must be answered are whether the concentrations of any analyte or combinations of analytes were: • Sufficient to cause the death? • Sufficient to have affected the actions of the decedent so as to have caused the death? • Insufficient to have any involvement in the cause of death? • Insufficient to protect the individual from an underlying mechanism of death such as an epileptic seizure?