Explosives: Types, Classification, and History

Explosives Mechelle C Gempesao CRI 311L Project Improvised Explosive Devices DUMMY power source Initiator Switch main charge , and a container Sample footer text 3/1/20XX 2  What are Explosives An explosive refers to a...

Explosives Mechelle C Gempesao CRI 311L Project Improvised Explosive Devices DUMMY power source Initiator Switch main charge , and a container Sample footer text 3/1/20XX 2  What are Explosives An explosive refers to a substance containing a large amount of stored energy, which is capable of undergoing a rapid chemical reaction. Sample footer text 3/1/20XX 3 What is explosion? A rapid increase in volume and release of energy in an extreme manner, usually with the generation of high temperatures and the release of gases. Sample footer text 3/1/20XX 4  History of Explosives vApproximately 1,000 years ago, the Chinese invented the first chemical explosive called gunpowder (also called black powder). v Gunpowder was the first form of chemical explosives and by 1161, the Chinese were using explosives for the first time in It consists of a mixture of sulfur, carbon (in the form warfare of charcoal) and potassium nitrate (saltpeter). Sample footer text 3/1/20XX 5 Classification of Explosives vExplosions are classified according to the source or mechanism by which the explosive pressures are produced. Sample footer text 3/1/20XX 6  Mechanical Explosives v A mechanical explosive is one that depends on a physical reaction, such as overloading a container with compressed air. Such a device has some application in mining, where the release of gas from chemical explosives may be undesirable, but otherwise is very little used. Sample footer text 3/1/20XX 7 Chemical Explosives vAn explosive chemical is a substance or mixture that experiences violent combustion as a reaction to an ignition source. Sample footer text 3/1/20XX 8 Kinds of Explosives (Explosive materials may be categorized by the speed at which they expand) vLow Explosives vHigh Explosives Low Explosives (Deflagrating) v Burn at a much slower rate and create less pressure. Low explosives are typically used as propellants to send a rocket into space or force a bullet out of a gun. (Burns or Deflagrate). Primer v In firearms and artillery, the primer is the chemical and/or device responsible for initiating the propellant combustion that will push the projectiles out of the gun barrel. v A volatile substance that ignites when struck to detonate the powder in a cartridge.  M107 artillery shells. (mixture of TNT and RDX) High Explosives Detonating explosives, such as TNT and dynamite, are characterized by (Detonating) extremely rapid decomposition and development of high pressure. Sample footer text 3/1/20XX 13 Sample footer text 3/1/20XX 14  v“ b l a s t i n g o i l ,” o r nitroglycerine was the first high explosive used in commercial blasting. v It is considered dangerous because it is an unstable chemical. Sample footer text 3/1/20XX 15 Sample footer text 3/1/20XX 16  Alfred invents “dynamite” “In the late 1800’s, Alfred Nobel combined a mixture of nitroglycerine (NG) with a special type of clay called kieselghur, which he packed into sticks. The resulting dynamites were the first type of high explosive that was safer to use. Dynamites do not accidentally explode when hammered, dropped, or burned. il Nobel’s Blasting O Sample footer text 3/1/20XX 17 v Dynamite Contents Nitroglycerin or NG Support compounds EGDN (ethylene glycol dinitrate) Ammonia-gelatin Sawdust wrapped in buff, red, white, or orange wax paper Sample footer text 3/1/20XX 18 vNitroglycerine Type of Dynamite The types of dynamites that use NG include the following: Straight Dynamite Ammonia Dynamite Gelatin Dynamite Ammonia-Gelatin Dynamite Sample footer text 3/1/20XX 19 v1. Straight Dynamite Its NG content makes it the most dangerous type of dynamite to handle and store NG vapor is quickly absorbed, thus causing severe headache Produces toxic fumes that make them unsuitable for underground or confined space blasting Handler should be extremely cautious if NG content is leaking Sodium nitrate is often added to it to supply oxygen and increase strength Has a velocity of 17,000 psi Has a heavy odor that is pungent yet sweet Sample footer text 3/1/20XX 20 v 2. Ammonia Dynamite Has a tan to light brown color Lower cost and less sensitive than straight dynamite Portion of NG is replaced by ammonia and sodium nitrate Percentage strength ranging from 5% to 70% Pushing heavy effect Detonation velocity ranging from 3,600 to 13,000 fps Possesses same odor effect as straight dynamite and may cause headaches resulting from the NG base Most widely used dynamite Sample footer text 3/1/20XX 21 v 3. Gelatin Dynamite Detonation velocities up to 23,600 fps Percentage strength ranging from 20% to 100% Unconfined, lower percentage strength that can detonate at 7,000 fps; confined percentage strength of up to 13,000 fps Consists of water - resistant gel made of sodium, nitrocellulose, and nitroglycerine Suitable for wet blasting on tough rock or ore Has a semi-gel consistency with properties shared with ammonia and ammonia-gelatin dynamites Sample footer text 3/1/20XX 22 v4. A m m o n i a - G e l a t i n Dynamite Similar characteristics as those of the gelatin dynamite, but uses less costly ammonium nitrate as part of the explosive mixture Percentage strength ranging from 25% to 90%. Detonation rate ranging from 7,000 to 13,000 fps Sample footer text 3/1/20XX 23 v 5. RDX Mixture C1: Composition 1 = RDX + plasticizer C2 = RDX + TNT + DNT + MNT + NC + dimethformamide C3 = C2 w/o DMF + tetryl C4 = RDX + secabate + fuel oil + polyisobutylene Sample footer text 3/1/20XX 24 v 6. Military Dynamite Equivalent to 60% straight dynamite Contains 75% RDX (Cyclonite) and 15% TNT (Trinitrotoluene), 5% engine oil, and 5% cornstarch Does not freeze or exude crystals Sample footer text 3/1/20XX 25 v 7. C4 Moldable Has a shattering effect Contains 91% RDX (Cyclonite), 8% plasticizer, and 1% other ingredients Detonation velocity of up to 26,400 feet/second Sample footer text 3/1/20XX 26 v 7. C4 Sample footer text 3/1/20XX 27  Velocity of Detonation "low explosive", such as black powder, or smokeless gunpowder has a burn rate of 171–631 m/s. In contrast, a "high explosive", whether a primary, such as detonating cord, or a secondary, such as TNT or C-4 has a significantly higher burn rate about 6900-8092 m/s. Sample footer text 3/1/20XX 28  Two Categories of Detonating Explosives v Primary Explosives v Secondary Explosives Sample footer text 3/1/20XX 29  1. Primary Explosives Primary explosives detonate by ignition from some source such as flame, spark, impact, or other means that will produce heat of sufficient magnitude Sample footer text 3/1/20XX 30  Initiating or primary explosives (Initiators) vThese types of explosives are highly sensitive to shock, friction or heat, and under normal conditions can detonate violently instead of burning. vAlso referred to as primers, blasting caps or detonators, primary explosives are generally used to set off other explosives and must be handled with great care. Sample footer text 3/1/20XX 31  2. Secondary Explosives Secondary explosives require a detonator and, in some cases, a supplementary booster. A few explosives can be both primary and secondary depending on the conditions of use. Sample footer text 3/1/20XX 32 Sample footer text 3/1/20XX 33  Non-initiating explosives v Compared with primers, non-initiating explosives are relatively insensitive to heat, friction or shock, and will normally burn than detonate when ignited in small quantities in the open air. v This group consists of the majority of high explosives used for military and commercial blasting. v Typical examples include dynamite, Trinitrotoluene (TNT), Cyclotrimethyltrinitramine (RDX), Pentaerythritol tetranitrate (PETN), and Tetryl (2,4,6-trinitrophenylmethylnitramine). Ammonium nitrate detonates at velocities between 3,300 feet/second, while HMX detonates at 29,900 feet/second. Sample footer text 3/1/20XX 34  Nuclear Explosions A nuclear explosion occurs due to either a fusion or fission reaction, which releases a large amount of heat and gas very quickly. The energy which is released heats the surrounding air and creates a blast wave. Regarding nuclear bombs, fusion and fission reactions are used within these. Sample footer text 3/1/20XX 35 Sample footer text 3/1/20XX 36  Characteristics of Explosives The standard qualities a compound or mixture must possess the following characteristics to qualify as an explosive: Generation of heat due to the exothermic reaction; Rapid expansion of gases; Can be controlled in terms of rapidity and initiation of the reaction when ignited; and Must have limited amount of toxicity Sample footer text 3/1/20XX 37  v A bomb is defined as a hollow projectile with a generally spherical shape, containing an explosive material and is made of iron. v It is fired by concussion or by time fuse. Sample footer text 3/1/20XX 38  Types of Explosion 1. Mechanical – This type of explosion is caused by the expansion of gas that produces high pressure beyond the capacity of the container. 2. Atomic or Nuclear – This type of explosion results from the atomic transformation of atomic elements. It undergoes three stages as follows: Fission - splitting of the nucleus of atoms; Fusion - under great force joining together the nuclei of atoms; and Tremendous release of energy, gas, heat, and shock 3. Chemical – This type of explosion is produced through the extremely rapid transformation of unstable substances accompanied by heat formation. Detonation refers to a violent explosion resulting from the practically instantaneous combustion or decomposition of unstable compounds. Sample footer text 3/1/20XX 39 Sample footer text 3/1/20XX 40 Sample footer text 3/1/20XX 41  Fire and Arson Investigation vFire and arson investigators examine the physical attributes of a fire scene and identify and collect physical evidence from the scene. This evidence is then analyzed to help determine if the cause of the fire was accidental or deliberate. vDuring the scene examination, investigators may find evidence such as accelerants, tampered utilities, and specific burn patterns, which may indicate criminal activity. Sample footer text 3/1/20XX 42  WHAT IS FIRE? vFire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products.  Fire is a rapid, self-sustaining oxidization process accompanied by the release of heat and light of different intensities. Sample footer text 3/1/20XX 43  Fire Triangle Theory - Three elements necessary to create/produce fire in equal proportion( heat,oxygen and fuel) Fire Tetrahedron Theory - The fourth element of fire known as the “Chemical chain reaction.” Life Cycle of Fire Theory- Stages / steps wherein fire is created. Sample footer text 3/1/20XX 44 The air we breathe is about 21% oxygen. Fire requires an atmosphere with at least 16% oxygen. FUEL HEAT OXYGEN  Categories of Fire v Natural Fire. Natural fire is the combustion produced when a fuel such as wood produces heat - a process called pyrolysis. This happens when there is not enough oxygen in the air (like in a forest fire). It produces large quantities of carbon dioxide and carbon monoxide and is therefore a critical function of natural fire. v Accidental Fire. Accidental fires are those in which the proven cause does not involve any deliberate human act to ignite or spread the fire. While in most instances, this classification is clear, some deliberately set fires can be accidental. For example, an engineer lighting off a boiler is purposely lighting a fire. v Incendiary Fire. A fire intentionally ignited under circumstances where the person knows the fire should not be ignited. Combustible capable of burning in air under normal conditions of temperature and pressure. v Arson. Any person who burns or sets fire to the property of another shall be punished by Prision Mayor under PD 1613. Sample footer text 3/1/20XX 46  Fire Investigation v The fundamental Origin and Fire Cause Objectives of a fire investigation are to: v 1. Determine the origin of the fire, the location where the ignition source and the fuel came together to start a fire. v 2. Determine the fire cause, the circumstances or conditions that brought the ignition source, fuel, and oxygen together resulting in the fire v 3. Assess the development and spread of the fire. v 4. In some cases, determine the responsibility for the fire, e.g., did it involve the negligence of some party or a product defect Sample footer text 3/1/20XX 47 Paraffin Test and Gun Powder Residue What is a Paraffin Test? qA paraffin test is a method used for detecting gunshot residue. This test determines whether or not a person has fired a gun, and is an important means by which to provide conclusive evidence in a clinical trial. qA paraffin test is also called Lunge’s test, Diphenylamine test, Dermal nitrate test, and the Gonzales test (Theo- doro Gonzales), named after the scientist who improved the test. Sample footer text 3/1/20XX 49 Dr. Gonzalo Iturrios v The paraffin test, originating from Cuba, was first employed by Dr. Gonzalo Iturrios when he used paraffin to collect and examine gunpowder residues from discharged firearms. v The basis of this test is the presence of nitrates in the gunpowder residue. Sample footer text 3/1/20XX 50 What is the ideal time allotment to perform a paraffin cast? 72 hours or 3 days Sample footer text 3/1/20XX 51 What is the positive result of paraffin test? “deep blue specks” Sample footer text 3/1/20XX 52 What reagent used in paraffin testing? Reagent used is Lunge’s Reagent which is prepared by dissolving 0.5grams of diphenylamine in 100 cc of C.P. sulfuric acid and adding 20cc of water otherwise known as DPA Reagent. Sample footer text 3/1/20XX 53 Other substances similar to nitrate—known as oxidizers—will also react with the reagent in the same way, thus giving a false positive result. These substances include the following: 1)1. Cigarette 2)2. Fertilizer 3)3. Tobacco 4)4. Explosives 5)5. Certain cosmetics 6)6. Urine 7)7. Food samples Sample footer text 3/1/20XX 54 Gunpowder Types of Gunpowder 1. Black powder – a mixture of carbon or charcoal (15%), sulfur (10%), and potassium nitrate (75%) 2. Smokeless powder – is either single base (composed of nitrocellulose) or double base (composed of nitrocellulose and nitroglycerine and other stabilizers) Sample footer text 3/1/20XX 55  Tests for Gunpowder Nitrates Sample footer text 3/1/20XX 56  What causes the blue specks when the paraffin cast is treated with diphenylamine reagent? Sample footer text 3/1/20XX 57 Sample footer text 3/1/20XX 58 1. Gunshot Range (GSR) Test When a gun is discharged, gunpowder residue may also be deposited on the clothing of the victim. The size and density found on the clothing as well as pattern of gunpowder will determine the appropriate distance of the firer to the victim. As the distance to the victim increases, the size of the pattern increases while density decreases. Sample footer text 3/1/20XX 59 2. Neutron Activation Analysis This refers to the use of access to the nuclear reactor and facilitates to determine radiation. Sample footer text 3/1/20XX 60  How can you determine if the firearm was recently fired? Sample footer text 3/1/20XX 61 3. Gunpowder Residue Test (GPR) Test Diphenylamine reagent is applied to cotton swabbing of the barrel and chamber of the gun to determine if firearms were fired. A deep blue color results from the reaction of nitrates with the reagent indicating presence of gunpowder residue. Sample footer text 3/1/20XX 68 4. Paraffin-Diphenylamine Test (Dermal nitrate test) vTaking a paraffin cast on the hands of the alleged gunman should be taken within 72 hours from the alleged time of firing. Here, the reagent used is Lunge’s reagent, which is prepared by dissolving 0.5grams of diphenylamine in 100 cc of C.P. sulfuric acid, and adding 20 cc of water otherwise known as DPA reagent. vA positive result is indicated by the presence of blue specks when the paraffin cast is treated with diphenylamine reagent. The blue specks are caused by the nitrates present in gunpowder. However, a positive finding is not conclusive evidence but only a corroborative one. Sample footer text 3/1/20XX 69 Sample footer text 3/1/20XX 70 Factors that affect the result of a paraffin examination: vLength of the barrel vType of caliber of ammunition vWind velocity and direction vAge of gun/efficiency of the mechanism vHumidity/percent moisture in air vUse of gloves vDirection of firing vPassage of 72 hours Sample footer text 3/1/20XX 71 Guidelines for Estimating Target Distances Sample footer text 3/1/20XX 72 Sample footer text 3/1/20XX 73 Sample footer text 3/1/20XX 74 In comparison, if the gun is discharged when held close to the body of the victim, it produces two types of discoloration: Sample footer text 3/1/20XX 76 1. Tattooing voccurs when the gun is held at about 36 inches away from the target vpresence of a black coarsely peppered pattern due to the partially burned and unburned particles of the gunpowder vthe size of the powder tattooing depends on the powder charge, caliber, and the distance of firing Sample footer text 3/1/20XX 77 2. Smudging voccurs when the gun is held about 2 inches to a maximum of 8 inches away from the target va dirty grimy appearance deposited around the entrance hole due to the soot from the burned powder vthe size of smudge depends on the caliber of the gun, type of powder used, length of the barrel of the gun, and the distance of the muzzle of the gun was held from the body Sample footer text 3/1/20XX 78 Sample footer text 3/1/20XX 79 What Is Toxicology? vToxicology refers to the science of detecting and identifying the presence of drugs and poisons in tissues, organs, and body fluids. vThere is a specialized area of toxicology called, toxicology, which deals specifically with animal, plant and microbial toxins; however, this is considered a science in its own right. Toxins are natural substances produced by living organisms, whereas toxic substances are synthetic substances from chemicals, which are considered toxicants. Sample footer text 3/1/20XX 80 An antigenic poison or venom of plant or animal origin especially one produced by or derived from micro organisms and causing disease when present at low concentration in the body. A. Tetanus B. Venom C. Toxin D. Poison Sample footer text 3/1/20XX 81 An antigenic poison or venom of plant or animal origin especially one produced by or derived from micro organisms and causing disease when present at low concentration in the body. A. Tetanus B. Venom C. Toxin D. Poison Sample footer text 3/1/20XX 82 History of Toxicology vThe history of toxicology dates back to the 16th century when Paracelsus stated that “all substances are poison.” vIn 1786 Plenck stated that “poison must be identified in the body.” vIn 1821, Mathieu Orfila of France, first classified the poisons and; v1836, arsenic was first extracted in a cadaver. Sample footer text 3/1/20XX 83 History of Toxicology vBy 1836, scientist James Marsh performed the first arsenic test, while in v1842, the Reinsch test for arsenic and mercury was designed. vIn 1850, tests for metals were conducted, and the Stratas-Otto, a method to extract alkaloid, was first introduced; vThis was followed by alcohol testing by examining the reduction of chromic acid. vFinally, in 1910, Dr. Alexander Gettler, a chemistry professor, started the field of forensic toxicology in the US. Sample footer text 3/1/20XX 84  Toxicology is used to verify if a case being examined is poisoning or if there is foul play in the crime scene, which may have caused the death of the victim. Importance of Toxicology Toxicology is an important tool in conducting criminal investigations that rely heavily on the analysis of toxins and toxic substances. Sample footer text 3/1/20XX 85  Tolerance and Idiosyncrasy Tolerance refers to the condition wherein a toxic substance does not affect the body the way it used to be (e.g., in the case of benzodiazepines, amphetamines, morphine, heroin, and methadone). Meanwhile, Idiosyncrasy is the opposite of tolerance, that is, small amounts can have fatal effects (e.g., in the case of aspirin, penicillin, cocaine, etc.) Sample footer text 3/1/20XX 86 Collection of Samples for Toxicology Examination There are many sources of samples for a toxicology examination, and these include the following: Lungs: aside from blood, lungs can also be checked for samples to determine solvent abuse Liver, kidney, brain, and fat: many drugs tend to concentrate on these areas Organs: these are sources for bodies that are already decomposed Hair and nail clippings: these are excellent sources of samples to determine heavy metal poisoning, such as arsenic, antimony, or thallium Kidneys: heavy metals often concentrate in the kidneys Lungs: excellent sources of volatile compound samples Vitreous humor: can be a source of alcohol/drug samples Brain: can be a source of samples of non-polar solvents, freon, or chloroform Blood: storage of blood should be -20 °C, fluoride+oxalate Sample footer text 3/1/20XX 87 Sample footer text 3/1/20XX 88  Intoxication via Alcohol vSources of alcohol include ethanol, which is produced by the enzymatic action of yeast on a vegetable substrate containing sugars. vAlcohol fermentation yields 12%–15% alcohol, while distillation concentrates alcohol to 40%–60%. vA breathalyzer is used to detect alcohol intoxication, especially among drivers suspected to be under the influence of liquor. Sample footer text 3/1/20XX 89 Sample footer text 3/1/20XX 90  What are Poisons? vA poison is a substance that, when introduced to the body, may cause changes that will result to injury and death. Sample footer text 3/1/20XX 91  Commonly Used Types of Poison vArsenic vHistorically, arsenic is a favorite killer poison. vIn the UK, arsenic is available to be purchased at a pharmacy to facilitate rat and pest management. When used as a poison, arsenic symptoms include vomiting, diarrhea with blood, and severe stomach discomfort. Sample footer text 3/1/20XX 92 A chemical compound that contains the cyano group, -C=N which consists of carbon atom triple-bonded to a nitrogen atom. Sample footer text 3/1/20XX 93  Cyanide vCyanide kills by preventing red blood cells from absorbing the sufficient amount of oxygen it needs. This resulted in a process known as “internal shortness of breath”. vDuring World War II, cyanide capsules were allegedly used by spies of World War II as an easy escape option to avoid persecution. Sample footer text 3/1/20XX 94 Types of Poisons 1. Corrosive poisons – they destroy tissues when they come in contact with the body (e.g., hydrochloric acid or muriatic acid) 2. True poison – natural poisons, such as cyanide present in silver cleaners 3. Cumulative poisons – poisons whose intensity lies on the gradual accumulation of the poison (e.g., arsenic). Sample footer text 3/1/20XX 95  Types of Poisoning One is acute poisoning, which refers to exposure to poison and produces immediate or instant death. The other one is chronic poisoning, which refers to the gradual exposure to the poisons and does not immediately result to death. Sample footer text 3/1/20XX 96 Sample footer text 3/1/20XX 97 Classifications of Poisons Sample footer text 3/1/20XX 98 1. Based on Origin a. Vegetable- poisons that comes from plants (e.g., Poison Ivy) Sample footer text 3/1/20XX 99 1. Based on Origin b. Animal- poisons transferred through bites and stings of terrestrial or marine animals (e.g., snake bites, sting from Jellyfish and bees) Sample footer text 3/1/20XX 100  c. Mineral- are strong acids 1. Based on Origin and bases (e.g., HCL and NaOH) Sample footer text 3/1/20XX 101 1. Based on Origin d. Microbial – are poisons produced by microscopic organism (e.g., bacteria in spoiled food and fungi found in expired bread) Sample footer text 3/1/20XX 102  e. Synthetic – are poisons chemically 1. Based on Origin produced in the laboratory that have useful importance to its purpose but become poisonous when taken into the body (e.g., pesticides and overdose of drugs) Sample footer text 3/1/20XX 103 2. Based on Chemical Properties Sample footer text 3/1/20XX 104  a. Metallic – are poisons that can be detected through isolation and extraction using solvent extraction and flame test like test for arsenic exhibits blue color on flame test. Sample footer text 3/1/20XX 105 Non-volatile Poisons – are poisons that can be analyzed through extraction using s o l v e n t s a n d confirmatory test with the use of Fourier Transformed Infrared Spectrophotometer (FT-IR) Sample footer text 3/1/20XX 106 c. V ol a t i l e P o i s o n s – a r e poisons that can be isolated through distillation; its distillate can be analyzed using GC-MS Sample footer text 3/1/20XX 107 d. Anions – are poisons that can be detected through qualitative m e t h o d s o f examination for the presence of anions (e.g., sulfates, sulphides, chlorine, and alkalis) Sample footer text 3/1/20XX 108 e. Miscellaneous – other poisons (e.g., pesticides, herbicides, and fertilizers) Sample footer text 3/1/20XX 109 3. Based on Physical Form a. Solid form may result to an overdose of sleeping pills and ingestion of dangerous drugs b. Liquid form are poisons introduced to the body (e.g., pesticides and cyanide present in silver cleaning agents) c. Gas forms include ammonia and bromine Sample footer text 3/1/20XX 110 4. Based on Physiological Effects a. Irritants- are poisons that result in nausea, vomiting, and diarrhea when they come in contact with the senses (e.g., chlorine, bromine) b. Corrosive- are strong acids and bases that can destroy the tissues that they come in contact to (e.g., HCL, NaOH) c. Neurotics –poisons can be Spine neurotics like picrotoxin and cerebrospinal Cerebral neurotics like alcohol, opium, and tobacco Cerebrospinal Neurotics further classified as - Deliriants such as cocaine - Depressants such as barbiturates d. Aesthetics/Exhaustives, such as aconite and KCN. Sample footer text 3/1/20XX 111 5. Based on Effects on the body a. Local destruction on the skin such as phenols and HCL b. Blood Poisons such as HCN c. Nervous poisons d. Cardiac poisons Sample footer text 3/1/20XX 112 Methods of Examining Poisons 1. Identification- this refers to screening and confirmatory tests that are used to identify the presence of the poisons. Screening test methods are done qualitatively by flame test, precipitation, as well as the identification of organic and inorganic cations and anions, metals, carbonlys, alcohols and aromatic hydrocarbons. Confimatory test is done with the aid of the machines in the laboratory like the GC-MS and Fourier Transformed Infrared Spectrometer (FT-IR). Sample footer text 3/1/20XX 113 Review Questions: (1/2 crosswise) 1.What is the role of toxicology in criminal investigation? 2.What are the main methods of collecting samples for toxicology examination? Sample footer text 3/1/20XX 114 Blood, Semen, and DNA Analysis Sample footer text 3/1/20XX 115 What Is Blood? v Blood circulates throughout the body and is made up of four elements, namely, the red blood cells or erythrocytes, the white blood cells or leucocytes, blood platelets, and plasma. v Human blood consists of 65% plasma, of which 90% is water and 10% are proteins (albumen, globulin and fibrinogen). Sample footer text 3/1/20XX 116  What is Serology? The preparation of testimony through the v Serology results is a branch via obtained of science that deals with the serology anddetermination its of the type and characteristics presentation in ofa blood, trial blood testing, by oraland andthewritten examination of bloodstain, testimony semen, saliva,by delivered and other body fluids that an expert may orismay witness thenot be involved main jobwithfunction DNA typing. of a forensic serologist. Sample footer text 3/1/20XX 121  Examination of Blood 1. Screening test Sample footer text 3/1/20XX 123  1. Confirmatory test a. Microscopic test – this is used to distinguish between mammalian, avian, piscine, and reptilian blood. Sample footer text 3/1/20XX 124  Examination of Blood Sample footer text 3/1/20XX 125  b. Microchemical test – this is a method of analytical chemistry that is used to study small samples of substances. Sample footer text 3/1/20XX 126  vc. Test to determine if blood is of human origin – this is done to detect precipitin, which reacts to human blood to form a precipitate; human blood contains precipitin. vd. Parentage test – this has several types as listed below. Sample footer text 3/1/20XX 127 Blood Grouping test - the blood of every human being belongs to one of four blood groups, which are known as groups O, A, B and AB. This blood group cannot be altered by the lapse of time or by the presence of a disease. Blood groups are hereditary and science has proven that the ABO system is one of the best ways in determining true parentage. Sample footer text 3/1/20XX 128 Bloodstain Pattern Analysis v Bloodstain pattern analysis (BSPA) refers to the examination of the shapes and the distribution patterns and locations of bloodstains, which can provide an interpretation of the physical events that gave rise to their origin. v Bloodstain pattern analysis (BPA) is the interpretation of bloodstains at a crime scene in order to recreate the actions that caused the bloodshed. Sample footer text 3/1/20XX 129  v a. Direc tion of travel: T h e d i r e c t i o n o f t r a v e l c a n b e determined by the bloodstain’s shape —the pointed end always faces its direction of travel. v b. Surface texture: The harder and less porous the surface, the fewer blood spatter produced v c. Origin of blood spatter: Origin in a 2D configuration can be determined by establishing lines through the long axis of individual bloodstains; the intersection of the lines represents the point from which the blood originated. v d. Impact angle: A drop of blood striking a surface at a right angle produces a nearly circular stain — as the angle decreases, the stain becomes more elongated. Sample footer text 3/1/20XX 130  Uses of BSPA v 1. Show assumptions concerning events and their sequence – Here, the position of the victim (which may indicate blood smears or blood trails) may show evidence of the struggle between the suspect and the victim. v 2. Confirm or refute statements made by principals in the case – Here, stain patterns on a suspects/victim’s clothing can help verify consistency with the accounts given by either the witnesses or the suspect. Sample footer text 3/1/20XX 131 Blood Fall Height What does the initial height of the blood drop do to the pattern of blood drops? - The higher the drop, the bigger the velocity and the larger the diameter. Sample footer text 3/1/20XX 132 Characteristics of a Blood Spatter v 1. Low velocity Spatter (5 f/s, 1.5 m/s) e.g., free-falling drops, cast off from weapon v The characteristics of a low velocity spatter are the pattern consists of large separate or compounded drops with diameters of 3 mm or more. Produced by minimal force and hits the surface with less than 5 ft/s velocity Dripping Blood from a wound. Sample footer text 3/1/20XX 133  2. Medium velocity Spatter (25–00 f/s, 7.5–30 m/s) e.g., baseball bat blows v The characteristics of a medium velocity spatter consists of small drops with diameters of 1 -3 mm. they travel at an average of 5 to 25 ft/s. They are commonly associated with blunt force trauma. Sample footer text 3/1/20XX 134 3. High velocity Spatter vThe characteristics of a high velocity spatter are that it consists of drops with diameters of less than 1 mm. vThis blood spatter hits at more than 100 ft /s. ve.g., gunshot, machinery Sample footer text 3/1/20XX 135 Three Categories of Bloodstain Sample footer text 3/1/20XX 136 1. Passive Bloodstains Drip – caused by dripping blood Drop – created by force of gravity - these are drops created or Pool – this refers to a change in the shape formed by the force of and direction of a bloodstain due to the gravity acting alone. influence of gravity or movement of the object Sample footer text 3/1/20XX 137  2. Transfer stains v A transfer bloodstain is created when a wet and bloody surface comes in contact with a secondary surface. Transfer pattern made by a bloody hand. v A recognizable image of all or part of the original surface may be observed in the pattern, as in the case of a Transfer stains result from objects coming into bloody hand or footwear. contact with existing bloodstains and leaving wipes, swipes or pattern transfers behind such as a bloody shoe print or a smear from a body being dragged. Sample footer text 3/1/20XX 138  3. Projected (Impact Stains) vImpact stains result from blood projecting through the air and are usually seen as spatter, but may also include gushes, splashes and arterial spurts. Sample footer text 3/1/20XX 139  Gunshot spatter v includes both forward spatter from the exit wound and back spatter from the entrance wound. vGunshot spatter will vary depending on the caliber of the gun, where the victim is struck, whether the bullet exits the body, distance between the victim and the gun and location of the victim relative to walls, floors and objects. vTypically, forward spatter is a fine Back spatter from a gunshot wound on a steering wheel. mist and back spatter is larger and fewer drops. Sample footer text 3/1/20XX 140  Cast-off vresults when an object swung in an arc flings blood onto nearby surfaces. vThis occurs when an assailant swings the bloodstained object back before inflicting another blow. vAnalysts can tell the direction of the impacting object by the shape of the spatter (tails point in the direction of Cast-off spatter patterns from a pipe and a pool cue. motion). vCounting the arcs can also show the minimum number of blows delivered. Sample footer text 3/1/20XX 141 Collection of blood stain Collecting Dried Blood Stains 1.You can cut out the portion where the bloodstain is located and package them into different paper envelopes. 2. Another technique that can be used is lifting. Place the fingerprint tape over the bloodstain, but do not use your bare hands to rub the tape. Lift the bloodstain as if it were a Fingerprint. Make sure the bloodstain will lift off the surface where it is located. Let’s Review v 1. What are the three components of blood? v 2. How will you determine if the stain is blood or not? v 3. If the stain is blood, what is the next step in blood examination? v 4. If the parents are both blood type is A; what will be the possible offspring? v 5. How do you determine if the blood is animal or human? QUESTIONS???  What is Semen? vSemen refers to the body fluid produced by the male sex organ, usually amounting to 2.5 to 6.0 ml seminal fluid per ejaculation. Each ml contains 100 million or more spermatozoa. Sample footer text 3/1/20XX 156  vThe semen is the viscid, albuminous fluid with faint grayish-yellow color, having the characteristic fishy odor, and containing spermatozoa, epithelial cells, lecithin bodies and other substances (Solis, 1987). Sample footer text 3/1/20XX 157 v Spermatozoon is a living organism, normally present in the seminal fluid consisting of a head, neck and tail. v It is from 50 to 55 microns in length. The head is ovoid and flattened when viewed in front and pearshape when viewed on the profile. The head is about 5 microns in length while the neck is very short. The tail is the longest part of the spermatozoon and consists of a long slender filament with tapering end. v The ciliary movement of the tail is responsible for the forward movement of the spermatozoon. Sample footer text 3/1/20XX 158 vPhysical and Chemical Properties of Semen Sample footer text 3/1/20XX 159  Forensic Characterization of Semen vA large number of criminal cases handled by a forensic lab often involve sexual offenses, making it necessary to examine exhibits for the presence of seminal stains. vThe forensic examination of semen follows a two-step process: v1. Location of the semen; and v2. Conduct tests to prove the identity of the one who produced it. Sample footer text 3/1/20XX 160 PROCEDURE: 1. Gross Examinations: v a. Inspection by means of the naked eye or with the use of the hand lens: v The stain is grayish-white to faint yellow in color. In fabrics, the area occupied is slightly depressed. It usually has a maplike contour with silvery appearance of the surface. It is hardened with shiny borders. Sample footer text 3/1/20XX 161  v b. Inspection by means of Ultraviolet light: v This method is resorted to in order to make visible, small seminal stains or patches. Determine the side of the clothings where the stains are located. Under ultraviolet radiation, the seminal discharge shows bluish fluorescence. Sample footer text 3/1/20XX 162 Forensic Examination of Semen and Seminal Stain v 1. Wet Specimen. Here, a drop of the fluid is placed on a glass slide to which a few drops of distilled water are added. This is then examined under a high-powered microscope to determine the presence of sperm cells or spermatozoa. A spermatozoon has a head and thin flagellate tail. Sample footer text 3/1/20XX 163 2. Dry Specimen a. Physical examination Dry semen has a stiff starchy feeling when deposited on a piece of clothing. It may have a slight deepening of color (grayish white sometimes yellowish) and disappearance of odor. It also exhibits bright bluish fluorescence under UV light. Sample footer text 3/1/20XX 164 2. Dry Specimen b. Chemical examination Florence test. Named after Dr. Florence of Lyons, uses potassium triiodide that results in the formation of crystals to indicate the presence of choline. Basis: Choline is detected in this method. (Seminal Origin) Sample footer text 3/1/20XX 165 2. Dry Specimen b. Chemical examination Barberio’s test. using picric acid as crystallizing agent, this results in the formation of spermine picrate crystals, which appear as slender yellow-tainted rhomboid needles with obtuse angles that may sometimes appear as ovoid crystals. Basis: Detection of Spermine (Prostates Origin) Sample footer text 3/1/20XX 166 2. Dry Specimen b. Chemical examination Acid Phosphatase test is a presumptive test for semen. It may be performed directly on a cut out portion of a stain, an extract of a stain, or a “wipe” of the stained material. If acid phosphatase is present, a purple color will appear within a short period of time (30 seconds). Weak stains may take between 1 to 3 minutes. Sample footer text 3/1/20XX 167  2. Dry Specimen v c. Microscopic examination- this test identifies sperm cells or spermatozoa, which indicate that the semen is of human origin; spermatozoa die as the semen dries. v In this test, the rapid stirring of a fabric-stain-water mixture will transfer a small amount of sperm into the water. A drop is then taken, dried, stained, and visualized under a high- powered microscope. Sample footer text 3/1/20XX 169  Microscopic Problems v 1. Some sexual crimes may involve males who have an abnormally low sperm count—this condition is called oligospermia. v 2. Sperm are very brittle when dried and tend to easily disintegrate. They are also difficult to remove from cloth material. v 3. Some males may suffer from aspermia, a condition where there is no sperm in their seminal fluid, which is due to a vasectomy. Sample footer text 3/1/20XX 170 2. Dry Specimen v d. B i o l o g i c a l exa m i n a t i o n - P r e c i p i t i n Te s t (Biological test of Farnum 1901): v this test is used to differentiate human from animal seminal fluid. It is also used to detect spermato precipitins. Sample footer text 3/1/20XX 171  What is DNA? v Deoxyribonucleic acid (DNA) is a molecule that contains all the genetic information used in the development and functioning of all known viruses and living organisms. DNA is a nucleic acid comprising of macromolecules essential for all known forms of life Sample footer text 3/1/20XX 172  DNA v Deoxyribonucleic acid (DNA) molecules contain the information all living cells in the human body need to function. v Apart from identical twins, each person’s DNA is unique. As such, it can be used as evidence to help convict a suspect of a crime, but also to clear an innocent person. Sample footer text 3/1/20XX 173  v DNA database v Created in 2002, INTERPOL’s DNA database currently contains more than 247,000 profiles contributed by 84 member countries. Our DNA database can match profiles in just minutes to internationally link and solve crimes such as rape, murder and armed robbery. Sample footer text 3/1/20XX 174 v Human DNA molecules are double-stranded helices that consist of two long biopolymers called nucleotides (guanine, adenine, thymine, and cytosine). v DNA is organized into long structures called chromosomes. v During cell division, these chromosomes are duplicated, providing each cell its own unique set of chromosomes. Sample footer text 3/1/20XX 175  DNA in Forensics v DNA found in semen, skin, blood, saliva or hair found at a crime scene is used to identify an individual, such as a perpetrator or the victim. This process is formally called DNA profiling, but may also be called “genetic fingerprinting.” Sample footer text 3/1/20XX 176 DNA in Forensics vDNA profiling was first developed in 1984 by a British geneticist, Sir Alec Jeffreys, and was first used in forensic science to convict Colin Pitchfork in the 1988 Ender by murders case. vThe ability to obtain genetic match from minute samples has led to a re- examination of a number of cases. Sample footer text 3/1/20XX 177 v DNA profiling can also be used to identify victims of mass casualty incidents by means of v Disaster Victim Identification (DVI). the internationally accepted term for the processes and procedures for recovering and identifying deceased people and human remains in multiple fatality incidents. v Done by the SOCO personnel to help identify the victims via their relatives through personal belongings, and to identify bodies or body parts in serious accidents and dental records. Today, DNA profiling is used to identify individual victims in mass war graves by finding matches with living family members. Sample footer text 3/1/20XX 178  Methods of DNA Profiling v 1. Restriction Fragment Length Polymorphism (RFLP) Analysis - One of the first methods used in finding out genetics used for DNA profiling. v It refers to differences (or variations) among people in their DNA sequences at sites recognized by restriction enzymes. Sample footer text 3/1/20XX 179 Methods of DNA Profiling v 2. Polymerase Chain Reaction (PCR) Analysis - It identifies specific DNA sequences of interest, wherein the DNA sample is denatured into separate individual strands. This method then replicates DNA into a millionfold in two hours or less. v PCR is a very sensitive technique that allows rapid amplification of a specific segment of DNA. PCR makes billions of copies of a specific DNA fragment or gene, which allows detection and identification of gene sequences using visual techniques based on size and charge. Sample footer text 3/1/20XX 180 Methods of DNA Profiling v 3. Short Tandem Repeats (STR) Analysis – short tandem repeat (STR) markers to establish identity of missing persons, confirm familial relations, and link persons of interest to crime scenes. It is a widely accepted notion that genetic markers used in forensic applications are not predictive of phenotype. v It uses highly polymorphic regions with short repeated sequences. It helps identify unrelated individuals. Matches (or variations) in several control-samples indicate relationships, such that the full DNA profiles should differ (except for twins), to prove that a person was not actually matched to their own DNA in another sample. Sample footer text 3/1/20XX 181  Methods of DNA Profiling v 4. Amplified Fragment Length Polymorphism (AmpFLP) Analysis - This technique is faster than RFLP analysis and uses PCR to amplify DNA samples. It relies on variable number tandem repeat (VNTR) polymorphisms to distinguish DNA samples from one another. It is relatively cheaper and easier to set-up and operate and has thus remained popular in developing countries. Sample footer text 3/1/20XX 182  vReview Questions: (1/2 Yellow Paper) v1. W h a t i s t h e r o l e o f s e r o l o g y i n c r i m i n a l investigation? v2. What are the different methods employed in conducting blood examination? v3. What is DNA analysis? What is its role in forensic investigation? v4. What are the different methods of DNA profiling? Sample footer text 3/1/20XX 183  Glass Fracture, Macro E t c h i n g , and Bullet Trajectory Sample footer text 3/1/20XX 184 What is Glass? vGlass consists of a mixture of silica (natural sand) and two or more alkaline bases, such as lime, soda, or potash. Glass may also contain other elements and metals, which are added for color, heat resistance, hardness, and other desired properties. Sample footer text 3/1/20XX 185 vGlass and glass fragments often take an important role in criminal investigations of such offenses as burglary, housebreaking, fleeing the scene of vehicle accidents, and others. Sample footer text 3/1/20XX 186 Sample footer text 3/1/20XX 187 Sample footer text 3/1/20XX 188  Types of Glass v Tempered glass is soda-lime glass and is used in side in rear windows in cars and is stronger than normal glass due to rapid heating and cooling of the glass surfaces. It's relatively safe in the case of accidents. v It breaks into small fragments rather than big, sharp shards. v Cookware glass like Pyrex is also tempered glass Sample footer text 3/1/20XX 189 Types of Glass v Laminated glass is also soda-lime glass and used in car windshields. It's a sheet of plastic sandwiched between two sheets of glass. Upon impact, it's likely to stay in all one piece. Sample footer text 3/1/20XX 190  v Glass bottles and house windows are also soda- Glass bottles lime glass but the heating process used here is the easiest and fastest thus when they break, the pieces break into relatively large shards. Sample footer text 3/1/20XX 191 v Crystal glass, like what champagne and wine glassware is made of is, is not the typical soda-lime ratios but contains up to 40% barium oxide or zinc oxide. It has a high refractive index and thus is sparkly to the eye :) Sample footer text 3/1/20XX 192 v Mobile device screens as with the ipad is made out of aluminosilicate glass. These screens are, once again, mostly silicon dioxide, like in glass bottles and windows but they also contain aluminum. With the right heating, melting and cooling process, these screens become strong, thin, and durable. Sample footer text 3/1/20XX 193  Glass fractures and glass fragments can provide information through which several types of determinations may be possible, such as those listed below. v 1. Investigators can determine whether a fragment of glass originated from a particular glass object that has been broken (e.g., a fragment of headlight lens found at the scene of a vehicle accident did or did not Sample footer text 3/1/20XX 194  2. Investigators can determine whether a glass fragment originated from a particular kind of glass object, such as a spectacle lens, headlight lens, or a window pane. Sample footer text 3/1/20XX 195  v3. Investigators can determine the origin and direction of a fracture, specifically, they can determine what caused it and the direction from which the causative force came. Sample footer text 3/1/20XX 196 v4. Investigators can determine the order in which the fractures occurred, such as in the event of multiple fractures, including bullet holes. Sample footer text 3/1/20XX 197  5. Investigators can determine the angle from which a bullet struck a glass object. Sample footer text 3/1/20XX 198 6. Finally, investigators can determine whether a particular glass object, such as a jar or a bottle, contained an inflammable or explosive substance. Sample footer text 3/1/20XX 199  Visual Distinction of Glass v When one looks at a piece of glass, there are several distinctions that can be readily observed with the naked eye. These include the following: v 1. Surface Texture v 2. Color v 3. Curvature (if any) v 4. Thickness Sample footer text 3/1/20XX 200 Sample footer text 3/1/20XX 201  The Strength of the Glass and the Glass Fracture v The strength of glass depends on its surface. As soon as the surface is penetrated, such as by using a diamond tip pencil, glass could break along that scratch line. Once the surface is damaged, the remaining material is easily cracked or fragmented. Sample footer text 3/1/20XX 202  Properties of Glass vGlass possesses properties that help a laboratory examiner analyze its composition. vFirst, glass seldom breaks squarely across but leaves convex/concave edges, or stress lines, on the fractured edges; vsecond, glass produce both radial (primary) and concentric (secondary) fractures when broken; and vthird, glass bends and stretches before breaking. Sample footer text 3/1/20XX 203 Types of Glass Fracture v As mentioned earlier, there are two types of glass fracture. v A r a d i a l o r p r i m a r y fracture (radiate outward) res em bles t h e s po ke o f a wheel, in which the radiating rod originates at a common point. v I n a c o n c e n t r i c o r secondary fracture, the radiating rods are connected with one another, Sample footer text 3/1/20XX 204  Factors to Be Determined in Glass Fracture v 1. Point of Impact: Here, the front of the glass can be determined through the accumulation of dust and dirt on the glass. v 2. Age of the Fracture v Fresh fracture – exhibits a regular pattern of radial and concentric fractures v Old Fracture – shows short extension lines at the end of the radial fractures Sample footer text 3/1/20XX 205  3. Direction of Impact or Force (Position of the Firer) va. Angle from the right (right to left) – heavy chippings on the left side of the glass vb. Angle from the left (left to right) – heavy chippings on the right side of the glass vc. Perpendicular shot – even distribution of chippings on the exit side of the glass Sample footer text 3/1/20XX 206  4. Cause of Fracture q Due to natural means – shows plain wavy lines q Due to mechanical means – shows a regular pattern of radial/ concentric fracture Sample footer text 3/1/20XX 207  Fractures made with a Blunt Object or Instrument q Examination of glass fractures caused by the impact of a blunt instrument or object will reveal a pattern of radial and concentric fractures. q The impact side can be determined by careful examination of the stress lines on the edges of both the radial and concentric fractures. q As an initial step, at least partial reconstruction of the object should be made, so radial and concentric fractures can be positively determined. Sample footer text 3/1/20XX 208  q On radial fracture lines, the portions of the stress lines on the rear side (the side opposite to the side of impact) are well developed and distinctly individual; whereas those on the front, or impact side, are much less so, tending to run together and lose their individuality. The 3-R rule applies. Sample footer text 3/1/20XX 209  3R RULE q Radial cracks give rib marks that make q Right angels on the q Reverse side from where the force was applied Sample footer text 3/1/20XX 210  qOn concentric fracture lines, the opposite condition will be found, with the well-developed and individually distinct portions of the fracture lines appearing on the front, or impact side. Sample footer text 3/1/20XX 211  Fractures caused by Heat q Fractures caused by prolonged or intense exposure to heat can be distinguished from those caused by impact. q fractures caused by heat do not show a regular pattern of radial and concentric lines. q heat fractures have a distinct wave shape. q Heat fractures will also show little if any, curve patterns (stress lines) along the edges. Expansion of the glass (stretching action) occurs first on the exposed side. Sample footer text 3/1/20XX 212 Sample footer text 3/1/20XX 213  Fracture Impacts q 1. On low-velocity impact q a. These are characterized by an increased number of well-developed radial fractures that are usually accompanied by concentric fractures surrounding the point of impact q b. Lower velocity penetrations (golf balls, rock, hammer, etc.) Sample footer text 3/1/20XX 214  2. High Velocity Impact q a. Often characteristic of high-velocity breaking forces, such as a rock from a slingshot or a bullet from a firearm q B. Typically produces an individual hole with limited radial fractures q C. Has a morphological resemblance to a “cone” with a greater amount of glass absent on the opposite side of the impact q d. Short and dense radial fractures Sample footer text 3/1/20XX 215 Sample footer text 3/1/20XX 216  Factors that Contribute to the Resulting Characteristics of the Fracture qa. Distance between the window and the “shooter,” which is related to the projectile’s initial and terminal velocity qb. Size and hardness of the projectile qc. Shape and density of the projectile qd. Thickness and the type of glass, which affect the type of fracture or perforation sustained by the window Sample footer text 3/1/20XX 217 Sample footer text 3/1/20XX 218 PRIMARY RADIAL FRACTURES 219 220  Value of Glass as Evidence qGlass and glass fragments could have relatively high value as evidence owing to the distinct variations in their physical properties and methods by which they have been manufactured. Sample footer text 3/1/20XX 221 222 223 224 225 226 Significance of determining the types of glass fractures ◉ To provide information about the events which took place, and assisting in proving or disproving a witness’s story. ◉ 2. Glass fracture patterns are associated with burglary, criminal mischief, shooting incidents, and fire scenes. ◉ 3. To evaluate the direction of impact force applied (from inside out or outside in). ◉ 4. To calculate approximate force of impact, angle of impact of force. ◉ 5. To determine the type of glass fracture, the sequence of firing, direction of firing, and the type of firearm for the projectile holes present. 227 228 229 GLASS FRACTURES 230 BULLET HOLE FRACTURE 231 232 MACRO-ETCHING 233  MACROETCHING ◉ Macro-etching refers to the application of a chemical solution on a metal surface and observing any reaction that may take place. 234 ◉ MACRO-ETCHING - The examination of the serial number of engine and chassis of a motor vehicle by a crime laboratory Technician by means of applying chemicals solution on the said serial numbers to determine whether there is tampering and or possible restoration of the tampered serial numbers. 235 Definition of Terms ◉ Concavity – refers to a depression or excavation below the general level. ◉ Alteration – refers to changes or modification made in anything. ◉ Grind – to polish or smoothen by friction ◉ Obliteration – to conceal an object’s identity ◉ Serial number – series of numbers punched or pressed into an item to distinguish it from another of the same type. It is sometimes preceded with letters and symbols. ◉ Engraved number – a number that is impressed on a metal surface using an electrical or mechanical gadget. ◉ Embossed number – a number that is raised in relief from the surface or produced as a raised design, pattern, or lettering on a plain surface, e.g. metal. 236 237 Purposes of Macro-Etching Macro-etching has several uses as stated below. ◉ 1. It is used to determine whether the serial numbers of motor vehicles or firearms are tampered. ◉ 2. It is used to restore the original serial number of an article in question. a. The criminal offender may destroy this identification by defacing this serial number through filing, chiseling, grinding, and filling in. b. Articles of economic value are identified by the specific details about the manufacturer (e.g., protection number or serial number). 238 Restoration In a criminal investigation, number restoration plays an important role because of the following reasons: ◉ 1. It could prove that the property found in the possession of the suspect is actually owned by the victim; ◉ 2. It could establish an investigative lead from the article/ property that may have been taken from the scene of the crime; and ◉ 3. It could resolve conflicting claims of properties recovered by investigators. 239 240 241 242 243 Thank you Sample footer text 3/1/20XX 244