Forensic Chemistry and Toxicology 2024-2025 PDF

 **Academic Year 2024-2025**  I. **COURSE NAME:** FORENSIC SCIENCE 3 -**Forensic Chemistry and Toxicology** **COURSE DESCRIPTION:** This course focuses on a comprehensive understanding of the fundamental principles of chemistry as applied...

 **Academic Year 2024-2025**  I. **COURSE NAME:** FORENSIC SCIENCE 3 -**Forensic Chemistry and Toxicology** **COURSE DESCRIPTION:** This course focuses on a comprehensive understanding of the fundamental principles of chemistry as applied to forensic science, the role of forensic chemistry and toxicology in the criminal justice system, the analysis of physical evidence to aid in criminal investigations and legal proceedings, and cultivating critical thinking and problem-solving abilities in forensic investigation to prepare students for careers in forensic science or related fields. II. **NO. OF UNITS: 5** Units -- 5 Hours Lecture/Unit III. **NO. OF HOURS PER WEEK:** 5 Hours IV. **RATIONALE:** This course will provide an opportunity for students to establish and advance their understanding of the major disciplines of forensic chemistry and forensic toxicology, with examples to demonstrate their specific contributions to the identification, collection, preservation, analysis, examination, presentation, and biological and chemical analysis of physical evidence for the effective dispensation of justice. V. **OBJECTIVES:** At the end of this course, the students are expected to: - Understand the fundamental principles of chemistry and toxicology as applied to forensic investigations. - Apply scientific methods and techniques to analyze physical evidence. - Interpret and evaluate forensic data to support legal investigations. - Communicate effectively, both orally and in writing, the results of forensic examinations. - Develop critical thinking and problem-solving skills in forensic investigations. - Adhere to ethical and legal standards in forensic science. - Identify and classify different types of physical evidence. - Understand to collect, preserve, and package physical evidence according to standard procedures. - Understand various analytical techniques to examine evidence. - Understand substances such as drugs, explosives, and poisons. - Determine the composition and origin of materials found at crime scenes. - Understand the application of instrumental analysis in forensic chemistry. - Explain the principles of toxicology and its role in forensic investigations. - Identify common poisons and their effects on the human body. - Collect and preserve biological samples for toxicological analysis. - Utilize analytical methods to detect and quantify poisons in biological specimens. - Interpret toxicological findings to determine the cause and manner of death. VI. **COURSE OUTLINE:** - Chapter I (Introduction to Forensic Chemistry and Toxicology) - Chapter II (Forensic Chemistry as applied to crime detection:Semen,Hair,Textile Fiber,Blood) - Chapter III ( Forensic Chemistry as applied to crime detection:Gunpower and Other Explosives,Chemical Aspects of Document Examination,Glass, and Glass Fragments and Fractures, Moulage and other Casting Techniques,Metallurgy, Flourescence Photography,Petrography ) - Chapter IV ( Forensic Toxicology) **\ ** **FORENSIC CHEMISTRY & TOXICOLOGY** **PRACTICE OF FORENSIC CHEMISTRY** The work of a Forensic Chemist is divided into four stages,namely: *1.Collection of the specimen* *2.The actual examination* *3.The communication of the results of the examination* *4.Court appearance* 1. **[Collection of the specimen to be examined]** *The proper collection, preservation and transportation of specimens are essential in the investigation of a crime. Hence, whenever possible, the chemist should personally collect all the specimens necessary for the examination. This particular stage of a Forensic Chemist's work is essential as questions regarding the collection, preservation and transportation of the specimen are raised during the trial.* **Factors that must be considered when collecting specimen for examination:** *A.Sufficiency of Samples* *B.Standard for comparison* *C.Maintenance of Individuality* *D.Labelling and Sealing* 2. **[Actual Examination of the Specimen]** *The first step in the examination of an article is to scrutinize it carefully and write down in the laboratory logbook/record book a complete description of the external appearance including the manner in which it is secured and the particulars of the sealing. If possible take a photograph of the specimen including the inner wrappings and take noted and recorded. All wrappers should be kept and preserved since questions concerning them may be raised in court during trial.* *The second step in the examination is to measure or weigh the object and all measurements and weights should be entered in the laboratory logbook/record book. The specimen should then be placed in the proper container or wrapper and must be kept in the proper evidence room.* *The third step is the laboratory examination which consist of the chemical , physical, and confirmatory tests.* 3. **[Communication of the results of the examination]** *The results of the examination conducted should be communicated with the requesting party in the form of a written report which must include an enumeration of facts on the specimen received for examination with detailed description of the packaging , sealing and labelling, date of receipt and from whom it was received, the purpose of the examination, the finding and conclusion.* 4. **[Court Appearance]** *The written report of the Forensic Chemist is usually supplemented by testimonial evidence in a later date if the case is brought to court or the fiscals' office. Since the testimonial evidence may be given weeks, months or even years after the examination and the written report have been made, it is not only permissible but indispensable that the chemist should refresh his memory by referring to his laboratory record book before presenting himself in court.* **Role of Forensic Chemist in the Scientific Investigation** *A **Forensic Chemist**, performs laboratory examination on physical evidence submitted to the crime laboratory in order to expedite the investigation of a crime by the investigating party. He/she has the following responsibilities:* 1.Conduct qualitative and quantitative determination of abused drugs as well as volatile substances. 2.Conducts chemical examination of explosives and/or explosive ingredients. 3.Conducts examination of paraffin cast and firearms to determine the presence of gunpowder nitrates. 4.Conducts gunpowder examination on clothing for possible gunshot range. 5.Conducts chemico-toxicological examination of human internal organs, gastric contents, blood,water, food sample and other substances 6.Conducts examination of fake products in cases of unfair trade competition. 7.Conducts blood alcohol determinations. 8.Examines urine samples and other body fluids for the presence of abused drugs. 9.Conducts researches related to cases being examined. 10.Testifies and gives expert opinion in court. 11.Gives lectures on Forensic Chemistry and Chemical-toxicology to various schools, universities, police training centers and investigating units. 12.Responds to queries of all investigating units and render expert opinion on matters related to the application of chemical principles for the purpose of assisting investigators to develops investigative leads. **Golden Rules in the Practice of Forensic Chemistry** ------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **1.Go Slowly** **2.Be thorough** **3.Take Notes** *Good work cannot be hurried, therefore, take all the time necessary to make the case complete no matter how urgent it may appear.* *Make careful and mixture examination of everything and do not be satisfied with a qualitative analysis if a quantitative one is possible. It always pays to do too much rather than too little and it is difficult to forensee what will or will not be required in court.* *Keep a full neat and clean record of everything seen and done.* **4.Consult others** **5.Use imagination** **6.Avoid complicated theories** *Many cases will lead the expert into paths with which he is not familiar and when this happens he should consult those who know better.* *An expert with a wide and uncontrollable imagination is considered as the most dangerous creature. Though his being imaginative is sometimes useful, an expert witness does not have to be solely imaginative but he has to be skilled in the field of Forensic Science. He must bear witness within the limits of science.* *The simplest explanation is fundamentally the right one. Interpretation of results is often the most difficult part of the expert's task that is why a wide knowledge and scientific experience are the essential elements to obtain the right forensic examination results.* ------------------------------------------------------------------------------------------------------------------------------------------- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- **Failure to consider the golden rules will contribute to destruction of evidence/ specimen. The other reasons of forensic disaster are:** - Improper packing of specimen. - Failure to identify the specimen. - Improper, precaution use in transmitting the specimen. - Improper preservation. - Lack of precautions to prevent tampering of the specimen. **FORENSIC CHEMISTRY** *That branch of chemistry, which deals with the application of chemical principles in the solution of problems that arise in connection with the administration of justice. It is chemistry applied in the elucidation of legal problems. It is chemistry used in courts of law.* +-----------------------------------+-----------------------------------+ | **[BRANCHES OF | **[BRANCHES OF FORENSIC | | CHEMISTRY]** | CHEMISTRY]** | +-----------------------------------+-----------------------------------+ | - *Organic chemistry* | - *Dangerous Drugs* | | | | | - *Inorganic chemistry* | - *Explosive examination and | | | principles* | | - *Analytical chemistry* | | | | - *Gunshot Residue* | | - *Physical chemistry* | | | | - *Forensic Toxicology* | | - *Biochemistry* | | | | - *Blood Alcohol and Drug Test* | | | | | | - *Examination of Counterfeit | | | Products* | | | | | | - *Arson Investigation* | | | | | | - *Macro Etching* | | | | | | - *Bullet Trajectory* | | | | | | - *Tools and other marks* | +-----------------------------------+-----------------------------------+ **[SCOPE OF FORENSIC CHEMISTRY]** - *It includes the chemical side of criminal investigation* - *It includes the analysis of any material the quality of which may give rise to legal proceeding.* - *It is not limited to purely chemical questions involved in legal proceedings.* - *It has invaded other branches of forensic sciences notably legal medicine, ballistics, questioned documents, dactyloscopy, and photography* ***What is the Role of the Forensic Chemist in Criminal Investigation?*** A. ***Performs*** analytical examination of different controlled substances such as dangerous drugs and explosive ingredients. B. ***Conduct*** gunshot residue examinations. C. ***Identifies*** different peculiarities from trace evidence. D. ***Examines*** body fluids for any degree of intoxication of alcohol, drugs and poisons. E. ***Analyzes*** fake products for unfair competition F. ***Prepares*** technical reports , prepares findings for court presentation and testifies concerning scientific facts. **[PHYSICAL EVIDENCE]** A*rticles and materials which are found in connection with an investigation and which aid in establishing the identity of the perpetrator of the circumstances under which the crime was committed or which in general assist in the prosecution of the criminal. It encompasses any and all objects that can establish that crime has been committed or can provide a link between a crime and its victims or a crime and its perpetrator.* **What are the Primary reasons which may contribute to the Destruction of Physical Evidence?** - Improper packing of specimen - Failure of identification of specimen - Improper, precaution use in transmitting the specimen. **Classification of Evidence:** 1. 2. 3. ***Direct Evidence*** - A kind of evidence that directly address to the senses of the court. ***Circumstantial Evidence-*** A kind of evidence that seeks to establish a conclusion by inferences from proven facts. ***Hearsay Evidence -*** A kind of evidence that proceeds not from the personal knowledge of the witness but from the mere repetition of what the witness heard from other people. ***What is Witness?\ **This refers to a person, other than the suspect, who is requested to give information concerning an incident or a person.* *He testifies in court, and he may be the victim, the complainant , the accuser, the source of information , or the observer of an occurrence.* ***What is Suspect*** *In an offense, is a person whose guilt is considered on reasonable grounds to be practical possibility.* **Who maybe a Witness?** ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ***ORDINARY WITNESS*** **EXPERT WITNESS** *State facts and may not express his opinions or conclusions. He may testify to impressions of common experiments such as the speed of a vehicle, whether a voice was that of a man, woman or child. Beyond this he is closely limited.* *One who posses a special skill, be it in art, trade or science or one who has special knowledge in waters not generally known to men or ordinary education and experiments; one who is skilled in some art and trade or science to the extent that he possesses information not within the common knowledge of man.* ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- ***What is the Difference between an Ordinary Witness with an Expert Witness?*** An ordinary witness can only state what is senses has perceived while an expert witness may state what he has perceived and also give his opinions, deduction or conclusion to his perception. An ordinary witness may not be skilled on the line he his testifying while an expert witness be skilled in the art, science or trade he is testifying. An ordinary witness cannot testify on things or facts he has not perceived except those provided for any law while an expert witness must testify on things which he has seen giving his opinions, deductions or conclusion on the statements of facts. ***What are the qualifications of an Ordinary Witness?*** - - - **[METHODS OF ANALYSIS IN FORENSIC SCIENCE]** ***1.Wet Method*** - requires much time and effort. ***2.High-Precision Method -*** This refers to the utilization of UV and IR Spectrometry. **[CHARACTERISTICS OF TOOLS AND TECHNIQUES USED IN FORENSIC SCIENCE]** 1.SENSITIVITY 2. SPECIFICITY 3. RAPIDITY ***PRINCIPLE USED IN FORENSIC CHEMISTRY*** A. ***Law of Individuality*** - every object , natural or man-made has unique characteristics and not duplicated in any other object. B. ***Law of Progressive Change*** - everything changes with the passage of time. C. ***Principle of Comparison*** - only "likes: can be compared. D. ***Principle of Analysis*** - Analysis of two or more sets to understand any difference. E. ***Law of Probability*** - All identifications, definite or indefinite, are made consciously or unconsciously based on probability.  ***[TECHNIQUES USED IN FORENSIC CHEMISTRY]*** ----------------------- ------------------------------------------- ***MICROSCOPY*** ***SPECTROGRAPHY*** ***PHOTOGRAPHY*** ***NEUTRON ACTIVATION ANALYSIS*** ***INVISIBLE RAYS*** ***X-RAY DIFFRACTION (XRD)*** ***CHROMATOGRAPHY*** ***DNA TYPING OR DNA PROFILING*** ***ELECTROPHORESIS*** ***ATOMIC ABSOPTION SPECTROMETRY (ASS)*** ----------------------- ------------------------------------------- *Rating: **\_\_\_\_\ ***   *Discussion:* **SEMEN AND SEMINAL STAINS** ***SEMEN AND SEMINAL FLUID*** is a whitish fluid of the male reproductive track containing spermatozoa. *Its part are:* - - - - - ***Where semen stain as evidence can be found?*** - **[Seminal Examination]** *There are four examinations for seminal stains or seminal fluid in the form of stains namely:* - - - - - - - **Elements which may obstruct detection of Spermatozoa** - *Nature of fabric* - *Age of stain* - *Condition to which the stain was exposed reaching the laboratory* - *Handling of the specimen* *Discussion:* **SALIVA** It is the secretion of the mouth that is important in digestion and comprise of cells and secretions from the salivary and parotid glands. ***HOW IS SALIVA DETECTED?*** 1.Enzyme that breaks down starch 2.Found in many body fluid ***TEST FOR PRESENCE OF SALIVA*** **1.STARCH-IODINE TEST**  Iodine is used to test for the presence of starch  The amylase in starch reacts strongly with iodine and from a DARK BLUE COMPLEX, while amylopectin develops a REDDISH-PURPLE COLOR. **2.DNA IN SALIVA** *Discussion:* **HAIR AND TEXTILE FIBERS** *Hair is a specialized epithelial outgrowth of the skin which occur everywhere on the human body except on the palm of the hands and the sole of the feet. Hair is not completely round but maybe oval flattened. Its width is not always the same along its length. It starts out pointed and narrow and then strays more or less the same.* ***Two kinds of Hair:*** *(1) Real hair- (2) Fuzz hair -* **Parts of Hair:** 1. *Roots- (2) Shaft - (3) Tip-* **Parts of Shaft:** *(1)Cuticle- (2) Cortex- (3) Medulla or Core-* **Hair Root:** 1. *Living Root -- (2) Dry Roots --* +-----------------------+-----------------------+-----------------------+ | **Examination of | **Comparison between | **Other Aspects of | | Human Hair** | Human and Animal | Hair Examination** | | | Hair** | | +-----------------------+-----------------------+-----------------------+ | *Color;* | ***[HUMAN]{.underline | *Determination of | | | }*** | characteristics | | *Length by actual | | Determination of | | measurement;* | *1.M.I. is less than | characteristics by | | | 0.5* | race;* | | *Character of hair ;* | | | | | *2.Medulla may not be | *Determination of | | *Width (breadth);* | present* | characteristics by | | | | sex;* | | *Character of hair | *3.Scale pattern is | | | tip if present;* | fine and each one | *Determination of the | | | overlaps the other | region of the body | | *Manner by which hair | more than 4/5* | from which the human | | had been cut* | | hair has been | | | *4.Pigment granules | removed;* | | *Condition of root or | are fine* | | | base or bulb of | | *Determination of the | | hair;* | ***[ANIMAL]{.underlin | approximate age of | | | e}*** | the individual.* | | *Character of | | | | cuticle;* | *1.M.I more than 0.5* | | | | | | | *Character of | *2.Medulla always | | | cortex;* | present* | | | | | | | *Presence of dye in | *3.Scale is coarse | | | hair;* | and overlaps less | | | | than ½* | | | *Determination of | | | | whether naturally or | *4.Pigment granules | | | artificially curled;* | are coarse* | | | | | | | *Character of | | | | Medulla;* | | | +-----------------------+-----------------------+-----------------------+ +-----------------+-----------------+-----------------+-----------------+ | ***Aspects of | | | | | Hair | | | | | Examination*** | | | | +-----------------+-----------------+-----------------+-----------------+ | ***Race*** | ***Sex*** | ***Region of | ***Age*** | | | | the body*** | | +-----------------+-----------------+-----------------+-----------------+ | a. ***NEGROID | a. Male hair | a. *Scalp | a. *Infant | | RACE | is | hair* | hairs are | | HAIR** - | generally | | fine, short | | contains | larger in | b. *Beard | in length, | | heavy | diameter, | Hair* | have fine | | pigment | shorter in | | pigment and | | distributed | length, | c. *Hairs from | are | | unevenly a | more wiry | eyebrow, | rudimentary | | thin cross | in texture | eyelid, | in chapter. | | section of | than t hat | nose and | Children's | | the hair is | of a | ear* | hair | | oval in | female; | | through | | shape hair | | d. *Trunk | adolescence | | is usually | b)Male hair | hair* | is | | kinky with | averages | | generally | | marked | approximate | e. *Limb hair* | finer and | | variation | ly | | more | | in the | 1 / 350 of | f. *Axillary | immature | | diameter | an inch in | Hair* | than and | | along the | diameter, | | hair but | | shaft.* | female hair | *g)Public | cannot be | | | averages | hair* | definitely | | b. ***MONGOLOI | approximate | | differentia | | D | ly | | ted | | RACE -** | 1 / 450 of | | with | | contains | an inch in | | certainly.* | | dense | diameter. | | | | pigment | | | *b)If it is | | distributed | | | noted that | | more or | | | the pigment | | evenly the | | | is missing | | Negroid | | | or starting | | race hair | | | to | | cross | | | disappear | | section of | | | in the | | the hair | | | hair, it | | will around | | | can be | | to oval in | | | stated that | | shape hair | | | the hair is | | is coarse | | | from adult. | | and | | | It is | | straight | | | common for | | with very | | | a | | little | | | relatively | | variation | | | young | | in diameter | | | person to | | along the | | | have | | shaft of | | | prematurely | | the hair | | | gray or | | usually | | | white | | contains a | | | hair(head | | heavy black | | | hair) but | | medulla or | | | not body | | core.* | | | hairs.* | | | | | | | ***c)CAUCAS | | | *c)The root | | IAN | | | of hair | | RACE -** | | | from an | | contains | | | aged person | | very fine | | | may show a | | to coarse | | | distinctive | | pigment, | | | degeneratio | | and more | | | n.* | | evenly | | | | | distributed | | | | | than is | | | | | found in | | | | | Negro or | | | | | Mongolian. | | | | | Cross | | | | | section | | | | | will be | | | | | oval to | | | | | around in | | | | | shape, | | | | | usually | | | | | straight or | | | | | wavy and | | | | | not kinky* | | | | +-----------------+-----------------+-----------------+-----------------+ 4. *Discussion:* **TEXTILE FIBERS** **Textile fibers-** *fibers that can be converted into yarns.* **Yarn-** *made of fibers which have been twisted together, linked thread.* **Classification of Textile Fibers** The two divisions of fibers are Natural fiber and Synthetic or artificial fiber. +-----------------------------------+-----------------------------------+ | **Natural fibers** | **Synthetic or Artificial | | | Fibers** | +-----------------------------------+-----------------------------------+ | *1)Vegetable fibers* | ***Organic*** | | | | | *2)Animal fibers* | *1)Cellulosic* | | | | | *3)Mineral fiber* | *2)Non-cellulosic* | | | | | | ***Inorganic*** | | | | | | *1)mineral fiber* | | | | | | *2)metallic fiber* | +-----------------------------------+-----------------------------------+ **Test Used for Fibers** **1.BURNING OR IGNITION TEST** *. A test that determines whether fiber is mineral, animal or vegetable. A single fiber is applied with flame at one end and the following are noted:* - - - - - - 2. **FLUORESCENCE TEST.** *frequently used to determine the general group to which a fiber belongs. It is not reliable for positive identification of fiber.* 3. **MICROSCOPIC EXAMINATION.** *fiber is placed on a slide teased and covered. In general it is the most reliable and best means of identifying fibers.* ***Characteristics of Common Textile Fibers*** ***1.Cotton** -- unicellular filament, flat, ribbon-like, twisted spirally to right or left on its axis; central canal is uniform in diameter. Cell wall thick, covered by a thick, structureless, waxy cuticle. Fibers taper gradually to a blunt or rounded point at one end.* ***2.Mercerized Cotton** -- straight, cylindrical with occasional twist; unevenly lustrous, smooth except for occasional transverse fold or wrinkles; cuticle mostly lacking.* ***3.Linen** -- multicellular filament, straight and cylindrical, not twisted and flattened, tapering to a sharp point. Cell walls thick, the lumen appearing as a narrow dark line in the center of the fiber to appear jointed resembling bamboo.* ***4.Cultivated silk**- smooth, cylinder, lustrous threads, usually single but often double, the twin filament held together by an envelope of gum. More or less transparent, without definite structure.* ***5.Wild silk-** similar to cultivated silk but broader and less regular in outline. Marked by very fine longitudinal striations with infrequent diagonal cross markings.* ***6.Artificial silk-** cylindrical, lustrous, appearing like a glass rod.* ***7.Wool-** easily distinguished by presence of flattened, overlapping epidermal scales not found on silk or any of the vegetable fibers.* 4. **CHEMICAL TEST -** ***Staining Test.*** *fiber is stained with picric acid, Million's reagent, stannic chloride or iodine solution.* ***Dissolution Test.*** if the fiber is white or light colored it is treated with the following chemicals. *Discussion:* **BLOOD AND BLOOD STAINS** **What is the importance of studying blood?** As circumstance or corroborative evidence against or in favor of the perpetrator of the crime. As evidence in case of disputed percentage As evidence in the determination of the cause of death and the length of time the victim survived the attack. Determination of the direction of escape of the victim or the assailant Determination of the origin of the flow of blood As evidence in the determination of the approximate time the crime was committed. **What is BLOOD?\ *Blood has been called the circulating tissue of the body.*** **Composition of Blood** **(45%)** *formed elements or the solid materials consisting chiefly of cells namely:* **A. RED BLOOD CELL** *Contains hemoglobin and carry oxygen to various cells in the body.* *The most abundant cells in our blood they are produced in the bone marrow and contain a protein called HAEMOGLOBIN that carries oxygen to our cells.* **B. WHITE BLOOD CELL** *Are masses of nucleated protoplasm.* *They are part of the immune system and destroy infectious agent called PATHOGEN.* *Helps to fight infection.* **C. PLATELETS** *The clotting factors that carried in the PLASMA, they clot together in the process called coagulation to seal a wound and prevent loss of blood.* **(55%)** *The fluid or liquid portion of blood where the cells are suspended. It is principally composed of:* **PLASMA** *A yellowish fluid of blood in which numerous blood corpuscles are suspended. A straw-yellow liquid formed when blood to which oxalate has been added to prevent clotting is allowed to strand.* **SERUM** *A straw -- yellow liquid formed when clotted blood is allowed to stand for sometime and the clot contracts.* **Problems in the Study of Blood** *Blood is difficult to be searched, the collection, preservation, packing and transportation of specimen suspected to contain blood is another. Blood offers little resistance to decomposition. It undergoes a rapid charge in its character with the passage of time as process of clotting and drying commences almost immediately on exposure to air.* **Blood Collection** ------------------------------------------ ----------------------------------------------------------- ***Fluid blood can be collected from?*** ***Where is dried blood or blood stains can be found ?*** ------------------------------------------ ----------------------------------------------------------- ***\ *** ***BLOODSTAIN PATTERN ANALYSIS*** *It is the examination of the shapes, locations and distribution patterns of bloodstains, in order to provide an interpretation of the physical events which gave rise to their origin.* *Bloodstain and patterns are useful for interpreting and reconstruction of events that occured during bleeding.* ***BLOODSTAIN PATTERN*** *A bloodstain pattern is a physical, geometric image created by blood contacting surface, or by a surface contacting blood.* *Meaning : The geometric images of interest are primarily those created once blood leaves the body* ***TYPES OF BLOODSTAINS DEPEND ON THE FOLLOWING (VADAT)*** - - - - -  **BLOOD DROPLETS CHARACTERISTICS** - - **SURFACE TENSION** - **\ ** **BLOODSTAIN PATTERN ANALYSIS TERMS** ***1. SPATTER -** Bloodstains created from the application of force to the area where the blood originated.* ***2. ORIGIN/SOURCE -** the place from where the blood spatter came from or originated* ***3.ANGLE OF IMPACT -** the angle at which blood droplet strikes a surface* ***4. PARENT DROP -** droplet from which a satellite spatter originates* ***5. SATELLITE SPATTERS-** small drops of blood that break of from the parent spatter when the blood droplet hits the surface.* ***6. SPINES-** the pointed edges of a stain that radiate out from the spatter; canhelp determine the direction from which the blood travelled.* ***7. FORENSIC SEROLOGY -** application of the study of blood,semen,saliva, and other body fluids to legal matters.* **CHANGES IN THE SHAPE OF BLOOD DROPLETS** - - - - ***Blood Examination*** **PRELIMINARY TEST.** determine whether the stain contains blood or another substance. Determines whether visible stains do or do not contain blood. It is used to demonstrate the presence of blood. **CONFIRMATORY TEST.** determines whether bloodstain really contains blood. Test that positively identifies blood. **PRECIPITIN TEST.** determines whether blood is a human or non-human origin, and if non human, the specific animal family from which it originated. **BLOOD GROUPING TEST.** determines the blood group of human. **THE PRELIMINARY TEST FOR BLOOD (COLOR TEST)** Benzidine Test or Benzidine Color Test Phenolphthalein Test Guaiacum Test Leucomalachite Green Test Luminol Test **Benzidine Test** *This is an extremely sensitive test that can be applied to minute stain. For many years the most commonly used preliminary test for blood. The Benzidine test never fails to detect blood even when very old, decomposed stain with all shorts of contamination is examined. The positive result is only indicative that the blood maybe present.* **REAGENT**: Benzidine solution ( small amount of powdered benzidine dissolved in glacial acetic acid) and 3% solution of hydrogen peroxide. **Phenolphtalein Test** *This is an alternative test to benzidine test. It can detect blood in a dilution of 1:80,000,000 parts. A positive results with this test is highly indicative of blood. The negative result is, therefore, valuable and is conclusive as to the absence of blood.* **REAGENTS:** Phenolphthalein solution (1 -- 2 grams phenolphthalein to 100 ml of a 25% KOH in water added with one gram zinc powder heated until colorless) and 3% solution of hydrogen peroxide. **Guaiacum Test** *A fairly delicate test showing the presence of fresh blood in a solution of 1:50,000 dilution. It may not react to very old stains.* **REAGENTS:** Fresh tincture of guaiac resin (Few lumps of this to 95% alcohol, then filter) and 3% of hydrogen peroxide or few drops of turpentine. **Leucomalachite Green Test** *This is a test not as sensitive as the benzidine test.* **REAGENTS:** Leucomalachite Green solution ( 1 gram leucomalachite green dissolved in 48 ml. glacial acetic acid and diluted to 250ml. water) and 3% hydrogen peroxide. **Luminous Test** *It is an important presumptive identification test for blood. The reaction of luminol with blood results in the production of light rather than color. By spraying luminol reagent onto a suspect item, large areas can be quickly screened for the presence of bloodstains. The sprayed object must be located in a darkened area while being viewed for the emission of light.* *Luminol test is extremely sensitive test. It is capable of detecting bloodstains diluted up to 10,000X.* **THE CONFIRMATORY TEST FOR BLOOD** The actual proof that stain is blood consists of establishing the presence of the characteristic of the red blood cells of the blood. **The three (3) confirmatory tests for blood are:** - **Microscopic Test -** Useful for the demonstration of blood corpuscles for making the distinction between mammalian, avian, piscine, and reptilian blood and for the investigation of menstrual, lochial and nasal charges. In short it differentiates mammalian, avian, piscine and reptilian blood. - **Microchemical Test** -- also known as Microcrystalline test which include Teichmann Hemin Reaction/Teichman Test/Haemin Crystal Test, Haemochromogen crystal Test or Takayama Test, Acetone-Haemin Test. One of the two popular microchemical test is the Takayama Test, a delicate test for the presence of hemoglobin. **REAGENT**: Takayama reagent (3 cc. of 10% NaOH, 33 cc. pyridine, 3 cc. of saturated glucose solution and diluted with 7 ml. of water. - **Spectroscope Test** -- is the almost delicate and reliable test for the determination of the presence of blood in both old recent stains. This is performed by means of an optical instrument known as SPECTROSCOPE. **THE PRECIPITIN TEST** *It is the standard test used to determine whether the stain/blood is of human or animal origin* Reagent: Precipitin/antiserum **BLOOD GROUPING AND BLOOD TESTING** **Principle of the Test** *All human beings have their blood belonging to any of the four principal blood groups. A normal suspension of human red blood cells when mixed with its own serum or serum of a similar group will make red blood cells when mixed with its own serum, or serum of a similar group will make red blood cells suspension remains even, but if suspended in the serum of another group, the red blood cells clump with one another, and this is called as agglutination.* *The RBC contain agglutinogens and the serum contains agglutinins.* **The Four Blood Groups** 1)Group "O" 2)Group "A" 3)Group "B" 4)Group "AB" **Landsteiner** *is the one who discovered the four blood groups. He named the four blood groups based on the antigen or agglutinogen content of the RBCs.* ***Value of the test*** *It may solve disputed parentage. A positive result is not conclusive that the one in question is the offspring, but a negative result is conclusive that he is not the child of the alleged parents.* **Inheritance of Blood Groups** *Knowledge of genetics will make it easier to understand the principle involved in the inheritance of blood groups. The inheritance of blood group is predetermined by the presence and absence of two facts or GENES called Gene A and Gene B.* **Inheritance Patterns of ABO Blood Group** **Application of Blood Group Data** - Questions of illegitimacy and relationships in may cause maybe solved by means of the blood groups as determined by the agglutinogens A, B, M, and N. - Determination of whether a man accused of fathering a child out of wedlock could or could not be its parent. - Determination of whether a child born of a married woman could or could not have been fathered by her legal spouse. - Determination of whether a child could or could not belong to a given set of parents in the case of accidental interchange of infants in a hospital. - Determination of whether a child who has been lost and later recovered after a long interval could or could not belong to a given set of parents. *Discussion:* **GUN POWDER AND OTHER EXPLOSIVES** *In the investigation of crimes involving the use of firearms, three most important problems may arise, the problems of:* - *Determination of whether or not a person fired a gun with bare hands within pertinent period of time* - *Determination of the probable gunshot range that is the distance the firearm was held from the body of the victim at the time of discharge.* - *Determination of the approximate time of firing of the gun on the approximate date of last discharge.* **Kinds of Gun Powder** **1.Black powder** - consisting of 15% of C, 10% of S and 75% of KNO3 or NaNO3. When black powder explodes KNO3 + c + S K2S + N2 CO2 **2.Smokeless powder** (which consist of cellulose nitrate or glyceryl nitrate combined with cellulose nitrate and some stabilizers. When exploded the following reaction occurs: C12H14O4(NO3)6 9CO + 3N2 + 7H2O + 3CO2 3.Cellulose nitrate 4C3H5(NO3)3 12CO2 + 10H2O + 6N2 + O2 4.Glyceryl Nitrate **Possible Location of Nitrates when black powder explodes:** - - - - **DIPHENYLAMINE-PARAFFIN TEST or DERMAL NITRATE or LUNGE'S DIPHENYLAMINE TEST** The test to determine the presence of nitrates, a test to determine whether a person fired a gun or not. A. B. **Possibilities that a person maybe found Negative for Nitrates even if he actually fired a Gun** - Use if automatic pistol - Direction of wind - Wind velocity - Excessive perspiration - Use of gloves - Knowledge of chemicals that will remove the nitrates **Possibilities that a person maybe found Positive for Nitrates even if he did not actually fired a Gun** - It is possible that the gunpowder particles may have been blown on the hand directly from the barrel of the gun being fired by another person. - An attempt to shield the body by arising the hand in some instances result in the implanting of powder particles on the hands of a person close to one firing a gun.. **How to determine probable gunshot range** The clothing is examined microscopically for possible powder residues, singeing, burning, smudging and powder tattooing. -------------- -------------- --------------- ------------------- ----------------- **SINGEING** **SMUDGING** **TATTOOING** **CARBON COLLAR** **GAPING HOLE** -------------- -------------- --------------- ------------------- ----------------- **Determination of the Probable time the Gun has been fired** In the examination / determination of the approximate time of last discharge we need the specimen firearm in the examination. **Specimen to be examined -** The barrel is swabbed with cotton and the residues examined under the microscopically and chemically. **Determination of the probable gunshot range** The clothing of the victim with bullet perforation should be submitted for possible gunshot range. **Factors Affecting the Presence and Amount of Gunpowder Residue** - Length of the barrel of the gun - Type and cal. Of ammunition - Wind velocity - Direction of firing - Distance of firing - Nature of firing - Humidity **THREE ZONES OF DISTANCES FROM WHICH A FIREARM IS DISCHARGED:** - Those in which the muzzle of the gun was held directly in contact with the body or practically so. - Those in which the muzzle of the gun was held about 2 to 36 inches away. - Those in which the muzzle of the gun was held away from a distance of 36 inches or more. **Held directly in contact** - gaping hold, smudging , singeing, tattooing. **Held from 2 inches to 8 inches** - smudging ,tattooing **Held from 8 inches to 36 inches** - tattooing **Held beyond 36 inches** - powder tattooing is seldom present. *Discussion :* **EXPLOSIVES** Explosive is any substance that may cause an explosion by its sudden decomposition or combustion. Explosive is also a material either pure single substance or mixture of substances which is capable of producing an explosion by its own energy. **CLASSIFICATION FROM THE VIEWPOINT OF CHEMICAL COMPOSITION:** - Inorganic compound. - Organic compound. - Mixture of oxidizable materials and oxidizing agents that do not explode separately. **Classification of Explosive (as to functioning characteristics)** **PROPELLANT OR LOW EXPLOSIVES -** Are combustible materials containing within themselves all oxygen needed for their combustion that burn but do not explode and function by producing gas that produces explosion. Examples are Black powder, smokeless powder, firecrackers, and pyrotechnics **PRIMARY EXPLOSIVE OR INITIATORS -** Explode or donate when they are heated or subjected to shock. They do not burn. Sometimes they do not even contain the elements necessary for combustion. The materials themselves explode and the explosion results whether they are confined or not. Examples are Mercury fulminate, lead azide **HIGH EXPLOSIVES -** Explode under the influence of the shock of the explosion of primary explosive. They do not function by burning, in fact not all of them can be ignited by a flame and in small amount generally burn tranquilly and can be extinguished easily. If heated to a high temperature by external heat or by their own combustion, they sometimes explode. Examples are Ammonium nitrate, TNT, dynamite, nitroglycerine, picric acid, plastic explosives. *Discussion*: **CHEMICAL ASPECTS OF DOCUMENT EXAMINATION** **DOCUMENT -** An original or official written or printed paper furnishing information or used as proof of something else. **Packing, Preservation and Transportation of Evidence/Documents** - Documents should be handled, folded and marked as little as possible. - If folding is necessary to send to the laboratory, the fold should be made along old lines. Place it in a Manila paper envelope or brown envelope or it can be placed in a transparent plastic envelope. - On receipt, the document should be placed between two sheets of plane white paper in folder. - Documents should not be touched with pencil, pen or anything that could possibly mark them. **The Examination of Questioned Documents** **Examination and Comparison of Paper** *The essential materials in a document examination of any kind are the paper and ink or pencil or writings. The examination of paper maybe necessary if we want to know the age of the document, the presence of alterations, erasures and other forms of forgery*. **Problems encountered in Document Examination/Analysis of Paper** - Determination of whether two pieces of paper originated from the same source. - Determination of probable age of paper. - Determination of the composition of paper. **Composition of Paper** Paper is made of three components namely: 1)Fiber Composition 2)Sizing Material -- to improve quality of paper 3)Loading Material -- to add weight to the paper Take Note: **EGYPTIAN PAPYRUS** - one of the earliest substances used for writing. It is form the name papyrus, that the word paper was derived. **FIBER COMPOSITION:** *Practically all papers maybe classified form the standpoint of their basic fiber composition into sets of fiber mixtures namely: Mechanical pulp-ground wood sulfate mixture, soda-sulfate mixture, rag sulfate* **SIZING MATERIAL:** *added to paper to improve its texture. Examples of sizing materials are rosin, casein, gelatin, starch.* **LOADING MATERIAL :** *added to paper to give weight. It partially fills the pores between the fibers of the paper. Examples are calcium sulfate and barium sulfate.* **The Four Tests for Paper** **1.Preliminary Test -** *the test deals with the appearance of the document and the following are observed:* *a)folds and creases* *b)odor* *c)impressions caused by transmitted light* *d)presence of discoloration and daylight and under ultraviolet light.* Take Note: - **WATERMARKS** -- *It Is a Distinctive Mark Or Design Placed In The Paper At The Time Of Its Manufacture By a Roll Usually a Dandy Roll.* - **WIREMARKS** - *Marks Produced On Paper By The Flexible Wire Soldered To The Surface Of The Dandy Roll That Carries The Watermark.* **2.Physical Test causing no Perceptible Change -** *A test applied on paper without perceptibly changing or altering the original appearance of the document.* *a)Measurement of length and width* *b)Measurement of thickness* *c)Measurement of weight/unit area* *d)Color of the paper* *e)Texture* *f)Gloss* *g)Opacity* *h)Microscopic Examination* Take Note: - **OPACITY** -- *the quality of paper that does not allow light to pass through or which prevents dark objects from being seen through the paper.* 3. **Physical Test causing a Perceptible Change** - *This is done only if sufficient samples are available and if proper authorization from the court is acquired this can be done.* +-----------------------------------+-----------------------------------+ | ***a)bursting strength test or | | | "POP" test*** | | +-----------------------------------+-----------------------------------+ | b. ***folding endurance test*** | | +-----------------------------------+-----------------------------------+ | c. ***accelerated aging test*** | | +-----------------------------------+-----------------------------------+ | d. ***absorption test*** | | +-----------------------------------+-----------------------------------+ **4.Chemical Test** - This test determines the fiber composition, the loading material and sizing material used in the paper. **a)FIBER COMPOSITION --** *examination is purely microscopic and it determines the material used and nature of processing.* **b)LOADING MATERIALS** -- *is determined by burning and ashing a portion of the paper and then the ash examined.* **c)SIZING MATERIAL** -- *gelatin is extracted by boiling the paper in water and the solution treated with tannic acid; rosin is extracted by heating the paper with 95% alcohol. The alcohol evaporated and the residue treated with acetic anhydride and strong sulfuric acid; starch is determined by addition of dilute iodine solution; case in is determined by addition Millon's reagent.* **The Analysis of Ink** *Some of the most important questions that arise in the analysis of inks are:* - *Whether the ink is the same or like or different inking from ink on other parts of the same documents or other document.* - *Whether two writings made with the same kind of ink were made with the identical ink, or inks of different qualities or in different conditions.* - *Whether an ink is as old as purports to be* - *Whether documents of different dates or a succession of differently dated book entries show the natural variations in ink writing or whether the conditions point to one continuous writing at one time under identical conditions.* **Types of Ink** **1)Gallotannic ink or iron-nutgall ink** -- *the type of ink where age maybe determined. Today the most frequently used ink for making entries in record books and for business purposes. Gallotannic ink is made of a solution off iron salt and nutgall. This ink can penetrate into the interstices of the fiber and not merely on the surface, thus making its removal more difficult to accomplish.* **2)Logwood ink** -- *made of saturated solution of logwood to which very small amount of potassium dichromate is added. Hydrochloric acid is added to prevent formation of precipitate. Phenol is added as preservative. This ink is inexpensive and does not corrode steel pen. Will not wash off the paper even fresh, flows freely.* **3)Nigrosine Ink or Aniline Ink** -- *made of coal tar product called nigrosine dissolved in water. It easily smudge, affected by moisture, maybe washed off from the paper with little difficulty. It is best determined by spectrographic method.* **4)Carbon ink or Chinese ink or India Ink** -- *the oldest ink material known. Made of carbon in the form of lampblack. Does not penetrate deeply into the fibers of the paper so that it may easily be washed off. Not affected by the usual ink testing reagents.* **5)Colored writing ink** -- *today, almost all colored inks are composed of synthetic aniline dyestuff\'s dissolved in water. In certain colored inks ammonium vanadate is added to render the writing more permanent.* **6)Ball Point Pen ink** -- *made of light fast dyes soluble in glycol type solvents as carbitol, glycol or oleic acid. Paper Chromatography is the best way of determine this type of ink.* **Determination of Age of Document** **1.Age of Ink** *-- no definite procedure which can be given for this determination except when the color is black, because on the observation that within a few hours, the color of ink writings becomes darker because the dye contain therein is influenced by the light of the room, oxygen of the air, acidity or alkalinity of the paper. There are several methods of determining the degree of oxidation of the ink writing and apparently these methods depend upon:* a)Physical phenomena such a matching the color of the ink writing with the standard colors of with itself over a period of time. b)Chemical reaction that may reveal some information concerning the length of time the ink has been on the paper. **2.Age of paper** *through watermarks in certain case from the composition of paper* **Other Aspects of Document Examination** **ILLEGIBLE WRITINGS** -- *unnecessary writings that are not capable of being read usually made on checks, birth certificate, passport and transcript of record.* **Some Illegible Writings:** **a)Erasure** -- *means removal of writing from the paper. Can be made chemically or* *mechanically.* **b)Obliteration** -- *the obscuring of writing by superimposing ink, pencil or other marking* *material.* **c)Sympathetic Ink or Invisible ink** -- *substances used for invisible writing.* **d)Indented Writing --** *term applied to the partially visible depression appearing on a sheet of paper underneath the one that the visible writing appears.* **e)Writings on Carbon Paper** -- *used sheets of carbon paper can be made readable.* **f)Contact Writing --** *black paper may contain traces of ink because of previous contact with some writings.* **Test for Ink** **1)Physical Test** -- applied to determine the color and presence of alterations, erasures, destruction of sizes with the use of stereoscope, handlens or microscope. **2)Chemical Test** -- a simple test wherein different chemicals or reagents are applied on the ink strokes and the chemical reactions or characteristic color reactions or other changes in the ink is observed. Reagents used: 5% HCI, 10% oxalic acid, tartaric acid, 2% NaOH, 10% NaOC1, C12, H2O, KCNS, water. **3)Paper Chromatography** -- a reliable procedure that can be adopted to identify and compare ballpoint pen ink. *Discussion:* **GLASS AND GLASS FRAGMENTS AND FRACTURES** **What is GLASS?** *Glass is a super cooled liquid that possess high viscosity and rigidity. It is a non-crystalline inorganic substance.* **Composition of Glass** *Glass is usually composed of oxides like **SiO2 (silica), B2O3 (boric oxide), phosphorus pentoxide (P2O5).** For commercial use silica is the most important oxide. It is the base of commercial glasses. It is made of silica sand and other metallic oxides. Oxide is for fluxing, durability and reduction of viscosity. Glass like window and plate that are made in mass production is fairly uniform in composition. These may contain incidental impurities and the presence of these substances in invaluable for the identification and comparison of glass by spectrographic analysis. Glass has also presence of trace elements which maybe sufficient to establish or negate the fact of a common source of two samples of glass.* **Analysis/Test for Glass** **1)SPECTROGRAPHIC TEST** *-- an instrumental method of analysis that determines the presence of trace element. Shows the constituent elements of a glass. It will not give sufficient information to establish the origin of the samples examined. A rapid examination and an adequate method for glass analysis since it requires only a small amount of sample.* **2)X-RAY DIFFRACTION ANALYSIS** *-- not as effective as the spectrographic analysis. Determines the type of pattern of glass. The type of pattern depends upon the composition of glass.* **3)PHYSICAL PROPERTIES EXAMINATION** *-- the most sensitive method of determining differences of composition in glass samples and it depends upon the study of the physical properties of glass. Properties like specific gravity or density, refractive index.* **4)ULTRAVIOLET LIGHT EXAMINATION --** *determines the differences in the appearance of their fluorescence thus indication of physical and chemical differences.* **5)POLISH MARKS --** *optical glass and other fine glassware are usually polished. In the polishing of glass fine marks are often left on the surface that can sometimes serve as a basis of comparison.* **Glass as Evidence of Crime** 1. 2. 3. 4. **Analysis of Glass from Vehicle** *Hit and run accidents represent a good percentage of crimes. If an automobile or any vehicle for that matter is discovered in which fragments of the lens can be found, a comparison maybe made with the fragments found at the scene of accident employing the methods of analysis for glass.* **Analysis of Broken Windows** **Broken windows caused by bullet holes** *On one side of the hole numerous small flakes of glass will be found to have been blown away giving the hole the appearance of a volcano crater. Such appearance indicates that the bullet was fired from the opposite direction of the hole from which the flakes are missing.* - - **Broken windows caused by fist or stone or hurling projectile** *The direction of the blow in case a fist or stone smashed the window is quite difficult but the principles of radial cracks and concentric cracks or fractures will apply.* **The Principle of 3Rs Rule for Radial Crack** **3Rs Rule --** *"Stress lines on a radial crack will be at right angle to the rear side of the glass."* **The Principle of RFC Rule for Concentric Crack** **RFC Rule --** *"Stress lines on a concentric crack will be at right angle to the front side" that is the side from which the blow came, rather than the rear side.*   *Discussion:* **MOULAGE AND OTHER CASTING TECHNIQUES** **What is a Casting Material**? *It is any material which can be changed from plastic or liquid state to the solid condition is capable of use as casting material.* The following are the criteria on which the value of casting material is assessed. 1)Must be readily fluid or plastic when applied. 2)Must harder rapidly to a rigid mass 3)must not be deformable nor shrink 4)must be easy to apply 5)must have no tendency to adhere to the impression 6)should have of fine composition and surface 7)should not inquire the impression 8)should be easily obtainable 9)should be cheap. The following are recommended formulas **1)Hastening** -- *add one half teaspoonful of the table salt to the plaster.* **2)Retarding** -- *add one part of a saturated solution of borax to ten part water to be used in making the plaster.* **3)Hardening** -- *to give a cast a greater durability it can be place on a saturated solution of sodium carbonate, and allowed to remain in the solution for sometime. It is then removed and dried.* **Tools Impression maybe classified into Two General Classes:** These produced by such instruments like an Axe-hammer, pliers and cutters which touch the area only once in producing the impression. **1)Compression Marks** -- *which produced by a single application of tool is the area of contact, for example: the impression of a single blow of a hammer.* **2)Friction Marks --** *which are series of scratches or striations produced by pushing a tool across the surface such as those produced by cutters jimmy or axe.* *Cast of Human Body is important that the temperature of the negative material should be below 110OF (43.3OC) a temperature higher than this will be uncomfortable if not injurious to the subject. Cast of the human body is made by the use of Negocoll and Hominit or Celert.* a. **Degocoll** -- is a rubbery gelatinous material consisting essentially of colloidal magnesium scaps. b. **Hominit** -- *is a resinous material used for making positives from Negocoll negatives. It is a flesh color and is used for external surfaces.* **c)Celerit** -- *is brown and is used for backing and strengthening the hominid.* *Discussion:* **METALLURGY (AS APPLIED TO CRIME DETECTION)** **METALLURGY** -- *is the art of extracting and working on metals by the application of chemical and physical knowledge.* **METALLOGRAPHY** -- *is a branch of metallurgy that involves the study of the microstructures of metals and alloys.* **Metallurgy is applied to criminal investigation such as in:** 1)Robbery 2)Theft 3)Hit and run 4)Bomb and explosion 5)Nail Examination 6)Counterfeit coins 7)Restoration of tampered serial numbers **Counterfeit Coins (coins made to imitate the real thing and used for gain)** **Two kinds of Counterfeit Coins** **1)CAST COINS --** *coins made in molds or coins made by casting method. An impression of genuine coin is taken by use of plaster of Paris, clay, or bronze. The plaster molds bearing the image of a good coin are filled within a low temperature alloy made with lead or tin. Sand molds are used for high temperature metals such as copper or silver alloys. Cast coin has poor imitation. It can be easily detected. The surface is usually pitted and uneven. The edges of lettering and designs are rounded instead of sharp.* **2)STRUCK COINS --** *made by striking or stamping method or these are coins made by means of dies. Consists of making an impression of a coin on a metal blank by pressure. Stamping is done by way of steel dies. Often well executed. Its detection is not easy since weight, specific gravity, composition may all be good. Careful comparison of smaller details of the designs with those of the genuine should be made.* **Standard Examination for Counterfeit Coins** *- by physical and chemical methods.* **Restoration of Tampered Serial Numbers** *Tampered serial numbers are restored by the application of etching fluid.* ***ETCHING FLUID --** f*luid used to restore tampered serial numbers. Choice of etching fluid depends on the structure of the metal bearing the original number. 1)For cast iron and cast steel -- 10% sulfuric acid and potassium dichromate 2)For wrought iron and forged iron-Solution 1 : hydrochloric acid + water + cupric chloride + alcohol and Solution 2:15% nitric acid 3)For aluminum-glycerin + hydrofluoric acid + nitric acid 4)For lead -- 3 parts glacial acetic acid and one part water 5)For stainless steel -- dilute sulfuric acid or 10% hydrochloric acid in alcohol for copper, brass, silver, and other copper alloys-ferric chloride + hydrochloric acid + water 6)For Zinc -- 10% sodium hydroxide 7)For Tin -- 10% hydrochloric acid 8)For Silver -- concentrated nitric acid 9)For Gold and Platinum -- 3 parts hydrochloric acid and one part nitric acid **Principle Involved in the Restoration and Tampered Serial Number** *When a number or any mark is stamped on metal, the crystalline structure of the metal in the neighborhood of the stamp is disturbed. This disturbance penetrates to an appreciable distance into the substance of the metal, but not visible to the naked eye once the actual indentations caused by the punch have been removed. When etching fluid are applied to this surface, the disturbed or strained particles of the metal differ in the rate of solubility than those of the undisturbed particles and this difference in solubility makes it possible in many cases, to restore the number to such an extent that they can be read and photographed.* **Trace Metal Detection Techniques (TMDT)** *A difficult problem in law enforcement is that of linking weapons ( particularly undischarged firearms), tools, and like object to specific individuals. The essential need for such identification in cases involving homicide, suicide, assault, burglary, robbery, and civil disorders has resulted in the development of a specific technique which shows whether an individual has been in contact with a particular metallic object. The technique can be conducted by police officers using simple equipment and the procedures described in this publication. Research has determined that metal object leave traces on skin and clothing surfaces in characteristic patterns with intensities proportional to the interaction of weight, friction, or duration of contact with metal objects. The Trace Metal Detection Technique (TMDT) makes such metal trace patterns visible when skin or clothing is treated with a test solution and then is illuminated by ultra violet light. Examination by ultraviolet light of the metal trace patterns which appear as fluorescent colors on the hands or clothing of the suspect allows a police officer to determine whether a suspect has been in contact with certain metal objects, the type of metal or metals in the objects, and also to infer what type of weapon or metal object was probably involved. The patterns fluorescent colors can be analyzed with refference to the circumstances requiring the use of TMDT and with other related information to provide an initial source of evidence. Physical evidence obtained by the use of TMDT, however, should be use as an adjunct to complete investigation.* **Selection of Test Areas** The areas to be examined are selected in relation to the circumstances, the suspect item (handgun, rifle, tools, bludgeon, etc.), and to the normal handling, use, possession, or concealment of the suspect item. For example, if the suspect item is a handgun, in addition to the hands those areas of clothing which may have been contact with the weapon and the skin areas directly beneath should be examined. In the latter case, metal traces and patterns are sometimes found to have penetrated clothing to the skin area beneath. **Application of TMDT Test Solution** The area to be examined is completely coated with the TMDT test solution. a spray container is generally the most suitable for this purpose. Whenever possible, the surface should be in a vertical position while being sprayed to prevent the formation of puddles. Although the TMDT test solution is nontoxic to skin surfaces, it should not be taken internally. Care should be taken to avoid spraying the solution into the subject's eyes. If spray does get into the eyes, the subject should immediately flush his eyes with water for at least ten minutes and obtain medical acid. **Drying the Test Area** *The test area is allowed to dry for a period of two or three minutes. The drying time of hands can be shortened by swinging the arms. Sunlight, breeze, and hot air also shorten the drying process. The areas on clothing and other materials should be allowed to dry thoroughly before examination.* **Examination of Test Area by Ultraviolet Light** The TMDT solution produces a light yellow fluorescent on those parts of the test are that have not been in contact with metal object. This pale yellow fluorescence provides a background for metal trace patterns seen on parts of the test area that have been in contact with metal objects. The metal trace patterns will give off fluorescent colors that are unique to types of metal and appear as silhouettes against the light yellow fluorescent background of the test area. Examples of fluorescent colors produced by various metals are: steel/iron (blackish purple),. Brass/copper (purple), galvanized iron (bright yellow), aluminum (mottled dull yellow), and lead (buff, flesh tone, or tannish). The officer first should identify the types of metal that have been in contact with the test area by the fluorescent color that appear under the illumination of the ultraviolet light. Essential to the officer's ability to make this identification is his knowledge and experience of what fluorescent colors are produced by metals such as steel, brass, copper, lead, aluminum, tin chromium, iron nickel, silver and certain alloys that can be contained in metal objects. After determining the presence of metal traces in the test area and identifying the metals, the officer can next determine the pattern of the metal traces revealed by the fluorescent colors. The location, size, and shape of metal traces on the hand from patterns that are characteristic of the size and shape and the normal way in which weapons, tools and other metal objects handled and used. The recognition of these patterns in conjunction with the determination of what metals left traces on the skin are the basis for identification of metal objects. In this way the officer can ascertain if the pattern is pertinent to a suspect item to its having been in the possession of a suspect. **Detection and Identification of Metal Objects on the Hands** The shape, size and weight of the metals object, the duration of contact, and the use of the metal object all combine to produce the location and intensity of metal traces and their patterns on the hands. On holding a metal object, metal traces depend on the object's shape and the size (more or less) of the hand that comes in contact with the metal surface. The intensity is also proportional tot he actions and forces involved in using a tool, striking blows with weapons, and the recoil from the discharge of firearms. In addition, the intensity is increased when the suspect resists action to disarm him. **Detection of Metal Objects on Clothing** As noted earlier, metals leave characteristic traces on clothing surfaces. Therefore, the suspect's clothing should be examined by TMDT. In particular, the areas to be examined are: gloves, hats, pocket, lining of coats, shirts, areas used for concealment, and other areas of clothing where the suspect item may have been carried, concealed, or otherwise been in contact. The spray is applied to the test areas placed in a vertical p\[position whenever possible. Clothing and other materials vary in their absorbency, therefore some of these test areas may require a heavier application of spray or two or more spraying to produce the maximum fluorescence and appearance of metal traces and patterns. The maximum appearance is obtained when a repeated spraying does not produce a brighter fluorescence that the previous spraying and drying of the test area. Metal traces sometimes penetrate clothing to the skin areas beneath. For example, metal traces may be found on the hands even though gloves have been worn while metal objects have been handled. Skin areas directly beneath clothing areas where metal traces have been found should be examined by TMDT. However, it should be noted the plastic, leather and rubber materials are impervious to penetration of metal traces. **Procedures for Detection and Identification of Handguns by TMDT** Because of their unique shape and use, handguns leave characteristic pattern and distinct signatures on the hands that are specific to types, makes, models, and calibres of these weapons. The police officers, with knowledge and experience in identifying the characteristic patterns and signatures on handguns by TMDT, can determine if a suspect has had a handgun in his possession and the signature of the handgun by the following procedures. **Spraying the Hands** The suspect's hands are extended from the sides of the body with the palms in a vertical position and the fingers and thumb separated and extended. The officer should make certain that the entire surface of the front and back of the hands are covered by the spray. **Examination of Hands** *The officer can next examine the suspect's dry hands under ultraviolet light. He should make a written record of the following observations and analysis of the suspect's hand:* *1)First, note and record the fluorescent colors of the metal traces that make up the pattern for the purpose of identifying the metallic content of the gun.* *2)Look for the appearance of metal traces (fluorescent colors differing from the light yellow fluorescent color produced by TMDT test solution) on those parts of the hand that come in contact with the gun: the index finger which rested on the trigger, the remaining fingers and thumb which enclosed the gun, the palm, and the degree of protrusion of the gun into the area between and beyond the junction of the thumb and index finger. (Extensive protrusion of metal traces beyond this area are made by the overhang at the top of the back edge of the handles of automatics, which is common to the design of this type of handgun.)* *3)Look for any irregularities or distinguishing marks in the pattern which may have been made by screws, protrusions, ornamentation's, and other markings of the gun.* *4)Look for interruptions in the pattern which may be due to nonmetal parts of the gun. Compare these observations with the suspect handgun or, if it has not been recovered, with a Catalog of Handgun "Signatures." This comparison serves to identify the signatures of the handgun or possession thereof by the suspect.* *5)Take a photograph of the pattern produced on the suspect's hand under illumination by ultraviolet light.* *6)If the suspect handgun has been recovered before the apprehension of the suspect or shortly after his arrest (it has been found that detectable metal traces may be found up to 38 -- 48 hours after contact with metal objects), the pattern of the handgun should be produced on a subject who has not recently handled a gun. The patterns on the subject's hands should be examined side-by-side under ultraviolet light to determine whether or not the handgun has been in the possession of the suspect. Photographs should be taken as evidence.* *7)If the suspect handgun has not been recovered, the pattern on the suspect's hand should be compared with the photographs of handgun patterns entered in a Catalog of Handgun "Signatures". A photograph of the pattern on the subject's hand should also be taken and compared with those in the catalog to aid in the possible identification of the type of gun the suspect has had in his position.* **Catalog of Handgun Signatures** *It has been noted earlier that handguns leave distinct pattern or "signatures" which are specific to types, makes, models, and calibres of these weapons. It is important that police officers develop a thorough knowledge and permanent record of these signatures. For this purpose a catalog of signatures should be prepared of as many types, models, makes, and calibres of specimen handgun that can possibly be obtained. The signatures of these handguns can be produced on the hands of subjects and examined under ultraviolet light as described above. A photograph of each signature is then entered ultraviolet light and the type, make and model of the specimen handgun.* **Detection of Tools and Metal Objects** *Some tools and other metal objects leave patterns that are characteristics of their shape, normal handling and use (for example: pliers, wrenches, shears, scissors, etc.) while other tools and metal objects may leave patterns that are similar because they are alike in shape and diameter (for example: crowbars, pipes, metal bars, etc.). Accurate analysis and determination of patterns on suspect's hands depend upon relating the above factors to circumstances, information, and evidence of the case upon the technician's experience and skill in using TMDT. Again, as an aid in obtaining such experience and skill, the technician should prepare a catalog of patterns and metal traces produced by tools and other metal objects.* **Contact with Non-Significant Metal Objects** The hands of individual may have metal traces from contact with metal objects such as handles, doorknobs, keys, etc. The intensities of the traces will be proportional to the force and duration of contact with these metal objects. In some cases, the metal traces will be faint because of momentary and light contact with the objects, but in other cases the traces from no significant metal traces and distort the patterns of significant metal objects. **Disassembly or Assembly of Handgun** *If the suspect has handled a handgun for these purposes, metal traces will be left on the hands which do not form the pattern ordinarily produced by the weapon. However, if the suspect held the weapon in the usual way for a period of time, the technician may be able to detect the specific pattern left by the handgun. ( It should be noted that gun oils give off a mother-of-pearl appearance under ultraviolet light.)* **Similar Patterns of Metal Objects** *Some metal objects may leave metal traces and patterns that are similar but not identical to the metal traces and patterns of the significant object. The officer should be mindful of such potential "false positives" and learn to discriminate accordingly.* **Exposure of Hand to Soap and Water** *Exposure to water after contact with metal objects does not affect an examination of the hands. Repeated hand washing with abrasive soap or rubbing with dirt after contact with metals will reduce the amount of traces deposited on the skin in a deliberate attempt to remove metal traces. However, it has been found that metal trace patterns may be found on the hands up to 36-48 hours after when the suspect has followed a normal routine of daily hand washings.* **Fluorescence Brightness of Metal Traces and Patterns** *The maximum fluorescence brightness of metal m traces and patterns that can be obtained in a TMDT examination depends not only upon the amount of metal that has been deposited on a skin or clothing surface but also upon the following factors: (1) adequate application and coverage of the TMDT test solution, (2) a strong source of ultraviolet illumination, (3) exclusion of all other illumination from the test area, and (4) the proximity of the ultraviolet light to the test area.* **Use of TMDT in the Field and or Group Screening** The successful use of TMDT in the field for checking on a suspect or screening a group of individuals for previous possession of weapons or other significant metal objects depends on whether the circumstances and conditions are suitable for such examination. The acquiescence or subjugation of the subject must be obtained to perform the examination. Sources of environmental light must be greatly reduced or eliminated in order to produce adequate fluorescence by ultraviolet light. And, finally, field personnel must have sufficient experience and skill to ascertain whether an individual has been contact with a weapon or significant metal object and whether an individual should be held for further detailed examination by TMDT. Studies should be carried out by police officers to determine the conditions and circumstances that prevent or are conductive to valid use and result of TMDT in the field. **Additional Use of TMDT** Another possible use of TMDT is the determination that a metal object has rested on another, non-metal object. For example, a research experiment involving the successful application of this use determined that (1) a pair of scissors no longer present had rested on the paper lining in a drawer and (2) coins no longer present had rested on a paper document in the bottom of a storage container. In the latter case, the duration of contact of the undisturbed coins was sufficient to show which side of each coin had rested on the document. Since friction is not involved, results depend of the weight and duration of the contact of the metal object with the surface on which it rests. When consideration is given ot the use of TMDT for this type of detection, the officer should conduct a test to determine if trace metal deposit can be produced on the surface in question. **Precautions** *Shortwave ultraviolet light in injurious to the eyes. Do not look directly into the light or shine the light into individual eyes. Protective goggles are commercially available that prevent passage of shortwave ultraviolet but transmit visible fluorescent light which is not injurious to the eyes.* *Discussion:* **FLUORESCENCE PHOTOGRAPHY** *It is commonly believed that ultraviolet photography is also fluorescence photography. Actually two types of photography are involved. The main purpose of ultraviolet photography is to record information about the objects that have the property of either absorbing or reflecting ultraviolet light or about objects in which two or more of its elements will absorb or reflect ultraviolet light to different degrees. These effects can be recorded photographically to show differences between objects or between areas of the same object. Whether or not the objects emit fluorescence does not enter into the purposes of ultraviolet photography. If a source of ultraviolet light is used to excite fluorescence in an object, photographing the fluorescent object is known as fluorescence photography. This type of photography is used for recording fluorescent metal trace patterns produced by TMDT*. **Photography Techniques** **1)Illumination.** *Efficient sources of ultraviolet light, placed as close to the subject as practical, should be used to excite the maximum fluorescence brightness of the object. The incidence of illumination of the object should be at an angle of about 45 degrees. Two sources (one on each side of the object) will provide twice as much light and prove more practical in photographing three dimensional objects.* 2. **Barrier Filter.** *This filter is placed in front of the camera lens to absorb the ultraviolet light radiation transmitted by the exciter filter and to transmit only the fluorescent given off by the object. An efficient barrier filter is the Kodak Wratten Filter No. 2A if the exciter filter transmits ultraviolet light only.* 3. **Exposure Determination.** *Because of the very low brightness of fluorescence, the proper exposures for photographing fluorescent metal trace pattern will have to be determined by tests. The beginner should take a number of photographs of subjects at various exposures. At fixed lens aperture, exposure time should be increased by a factor of two in successive steps over a wide range of increasing shutter speeds.* *A record of all exposure conditions should be made including: subject, ultraviolet source and its distance from the subject, filter, shutter speed, and lens opening. With a record of such officer can develop the know-how and skill in estimating the exposures for photographing subjects.* An extremely sensitive exposure meter can be used for determining exposures. However, its cell should be covered with a barrier filter to absorb ultraviolet light reflected from the subject which, if higher in brightness that the fluorescence of the subject, will give erroneous exposure settings on the camera. If the use of an exposure meter is feasible, the tests described above may not be needed to determine exposures. *Discussion:* **PETROGRAPHY AS APPLIED TO CRIME DETECTION** **PETROGRAPHY** -- *branch of geology that deals with the systematic classification and identification of rocks, rock forming minerals and soil. Also includes study of dust, dirt, safe insulation, ceramics and other such materials, both natural and artificial.* **Types of Soil** ---------------------- -- **Alluvial Soil** **Colluvial Soil** **Sedimentary Soil** ---------------------- -- **Collection and Submission of Evidence** *Soil usually in form of mud is usually recovered from shoes, slippers, clothes, tires, tools and furniture. If found on the above the soil should remain in place and the whole submitted to the laboratory. Should be wrapped in a clean paper or filter paper and placed in a box. Known soil samples should be taken at different places around the point of reference.* **Constituent of Soil** *1)Primary Minerals* *2)Clay Mineral* *3)Organic Constituents* -------------------------- -- **Primary Minerals** **Clay Mineral** **Organic Constituents** -------------------------- -- **ANALYSIS OF SOIL** *Several methods of petrography analysis that are being use in the laboratories to establish the identify of two or more samples of soil. There is no procedure that is specially recommended. It all depends on the availability of the apparatus. The DENSITY GRADIENT APPARATUS is a simple apparatus utilizing simple procedure in determining the identity or non-identity of soil samples based on the density distribution. The procedure is rapid, requiring a few hours of completion. It is sensitive to small changes in composition.* **Other Methods of Soil Analysis** **X-ray diffraction, spectrographic analysis and thermal analysis** are methods extensively used in commercial and private laboratories as general procedure. **Application of Soil Analysis to Scientific Crime Detection** *The value of soil as evidence depends wholly upon the fact that soils differ in various characteristics over the surface of the earth. This difference makes it possible to establish the identity or non-identity of two soil samples.* **DUST AND DIRT** **DUST AND DIRT** *-- has been described as "matter in the wrong place". The study of such piece of evidence may often provide the investigator with clues as to the occupation or previous whereabouts of a person under investigation.* - - - **Composition of Dust** *Whatever is the origin of dust and wherever it is found it always **contain substances of plant and animal origin and substances of mineral origin**.* **Classification of Dust** 1. ***For purpose of criminal investigation**, dust may well be classified from their source.* 2. ***Dust Deposited from the Air** - extremely fine dust particles present in the air everywhere. More in thickly populated and industrial region. Settle very slowly and ultimately deposited on any exposed surface. Its value in crime detection is significant.* 3. ***Road and Footpath Dust -** produced by the wear and tear of the road surface be vehicular and pedestrian traffic together with particles of soil carried by the wind or rain from adjoining regions.* 4. ***Industrial Dust -** industries ;like cement, button, powdered gypsum and plaster of Paris factories, flour milling, paint pigment, involves industrial processes like grinding, milling or beating for the purpose of producing finely powdered ultimate products which in the process impart a pronounced local character to the dust on the neighboring roads and buildings.* 5. ***Occupation Dust -** some of the finely powdered material maybe found on the clotting and foot wears of employees engaged in such industries. Aside from this for example, coal miner will have coal dust on his clothes, bricklayer will yield brick duct, sand and lime on his clothes.* *From the forensic chemical point of view, the identification of occupational dust is of great importance. In criminal investigation, the identification of the person through the articles of clotting left in the scene of crime or in a vehicle may place him in an identifiable class and thus to distinguish from the great majority of other persons. Such observation does not serve to distinguish the wearer of the cloth from all other persons.* **Collection and Submission of Dust and Dirt Specimen** *Dust and dirt present in clotting or objects that can be readily transported should be left in site. The whole article is packed in a clean box with proper protection and hipped to the laboratory.* If the object is immovable or too big to submit as a specimen like sofa, piano, dresses, the specimen maybe removed by mechanical means if present in large quantity. Dust on clotting maybe removed by the used of vacuum cleaner with paper bags used in the dust sack to collect the dirt. **Analysis of Dust and Dirt** 1)If the sample is very small, micro-chemical test or spectrographic analysis maybe employed. If the amount of specimen is sufficient the following is employed. 2)Examine the sample under the ultraviolet light 3)Treat a small quantity with a drop of water on a spot plate. 4)Observe of aqueous drop with hand lens 5)Note the proportion of the solid matters that remains in suspension and proportion that settles rapidly. 6)Reaction with litmus paper (aqueous drop) 7)Treat a small quantity with a drop of 0.1 NHCl. 8)Note evolution of gas 9)Note formation of precipitate 10)Note changes in color 11)Note materials dissolved by acid 12)Treat a small quantity with ethanol 13)Note color of alcohol drop 14)Note difference between color of an aqueous solution in procedure 2 and that in alcohol solution. 15)Note other changes **\ ** *Discussion:* **TOXICOLOGY** *The branch of science that defines the nature, effect, and detection of substance that is present to a specific matter.* **TOXIN** *A harmful compound that is usually produced by living cells or organisms and can cause disease or harm when introduced into the body's tissue.* **TOXICANT** *are synthesized chemical substances that impact biological functions in other organism.* **POISON** *A toxin that enters the body by being swallowed, inhaled , or absorbed through the skin."All substances are poisons. THere is none which is not a poison. The right dose differentiates a poison and a remedy" - Paracelsus (1532)* **VENUM** *A toxin that enters the bloodstream through injection or an injury.* **TOXINS ARE CLASSIFIED AS:** **A. BASED ON EFFECT:** **1. EXOTOXINS -** *toxin which are excreted by organisms.* **2.ENDOTOXINS -** *which are produced when bacteria are lysed.* **3. HEMOTOXIN -** *toxins that destroy red blood cells.* **4. PHOTOTOXIN -** *causes one to become photosensitive.* **5. BIOTOXINS -** *toxins that are biological in nature.* **B. BASED ON ORIGIN** *1. Animal/Toxin - a poison produced by living organism stimulating antibodies.* *2. Vegetables* *3. Mineral* *4. Microbial* *5. Synthetic* **According to Chemical Properties** **INORGANIC POISONS** *****Volatile and Non-volatile Poisons* *Mineral Acid* *Mineral Alkali* **ORGANIC POISONS** *Volatile*