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Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 9781449691790_CH04_FINAL.indd 82 28/10/13 9:42 AM © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTIONCHAPTER The Microscope © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC and ForensicNOT FOR SALE OR DISTRIBUTION 4NOT FOR SALE OR DISTRIBUTION Identification© Jones & Bartlett Learning, LLC of © Jones & Bartlett Learning, LLC Hair,NOT FOR SALE Fibers, OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FORand SALE OR DISTRIBUTION Paint NOT FOR SALE OR DISTRIBUTION OBJECTIVES FEATURES In this chapter you should© Jones gain an & understanding Bartlett Learning, of: LLCOn the Crime Scene—Serial© Jones & Bartlett Learning, LLC ● The parts of a compoundNOT FOR microscope SALE and OR how DISTRIBUTION Murderer Everett BellNOT IdentifiedFOR SALE OR DISTRIBUTION it works by “Nubs” ● The use of a comparison microscope to compare two objects See You in Court ● ©The Jones large working & Bartlett distance Learning, and the larger LLC © Jones & Bartlett Learning, LLC Back At the Crime Lab NOTdepth FORof field SALE afforded OR by theDISTRIBUTION stereomicroscope NOT FOR SALE OR DISTRIBUTION ● Differentiation of amorphous and crystalline materials by use of a polarized light microscope ● The structure of hair and the microscopy tech- WRAP UP niques used to identify human hair © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC ● The characteristics of natural fibers, human- Chapter Spotlight NOT FOR SALEmade OR fibers, DISTRIBUTION and the fabrics made with both NOT FOR SALE OR DISTRIBUTION types of fibers Key Terms ● The composition of different types of paints and how paint samples are characterized Putting It All Together ● The use of microspectrophotometers© Jones & Bartlett and scan- Learning, LLC © Jones & Bartlett Learning, LLC ning electron microscopesNOT FOR in the SALE forensic OR lab DISTRIBUTIONFurther Reading NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 9781449691790_CH04_FINAL.indd 83 28/10/13 9:42 AM © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTIONYOU ARE THENOT FORENSIC FOR SALE ORSCIENTIST DISTRIBUTION The microscopic techniques used to investigate trace fiber and hair evidence focus on their morphology. Morphology is a term that is used© Jones to describe & Bartlettthe size, shape, Learning, and color LLC of the evidence. The methods© employedJones &for Bartlett morphological Learning, LLC comparisons of questionedNOT FOR and controlSALE samples OR DISTRIBUTION often are used to show that two samplesNOT do not FOR match. SALE Indeed, OR more DISTRIBUTION suspects are exonerated by morphological comparison than are implicated by it. Only very rarely will the examiner be able to confirm that the individual who left behind the questioned trace sample was the same person who is the source of the control sample. © JonesThe utility & ofBartlett morphological Learning, comparison LLC methods is limited because© morphology Jones & often Bartlett is not capableLearning, of individual LLC - izingNOT hair FOR and fibers.SALE When OR twoDISTRIBUTION samples are similar enough to have originatedNOT FOR from SALEthe same OR person, DISTRIBUTION additional tests must be performed to establish their origin. 1. A bank was robbed by a man wearing a black ski mask. In a subsequent search of the bank parking lot, police re- covered a black ski mask. What trace evidence might be present? How should that evidence be investigated? © Jones & Bartlett2. The examinersLearning, at the LLC forensic lab found a short,© brown Jones beard & hair Bartlett inside theLearning, ski mask. ShouldLLC the investigators NOT FOR SALEfocus OR theirDISTRIBUTION search on men with brown beards? NOT FOR SALE OR DISTRIBUTION Introduction© Jones & Bartlett Learning, LLC Magnifying Small© Jones Details & Bartlett Learning, LLC During the searchNOT of aFOR crime SALE scene, OR investigators DISTRIBUTION Forensic scientists oftenNOT are FORconfronted SALE with OR the DISTRIBUTION will inevitably encounter many types of physical need to analyze many different types of materials evidence. Although the search may initially focus obtained during criminal investigations. The iden- on large objects that may prove to be evidence, tification or comparison of minuscule traces of a trace© Jones evidence & Bartlett must not Learning, be overlooked. LLC Trace evi- wide range© Jones of materials & Bartlett is a common Learning, occurrence LLC denceNOT FORis a generic SALE termOR DISTRIBUTIONused to describe small, in a modernNOT crimeFOR SALElab. The OR earliest DISTRIBUTION detectives— often microscopic, objects that are readily trans- including the fictional Sherlock Holmes—used ferred between people and places. The range of magnifying glasses to carefully examine evidence in objects falling into the category of trace evidence is the field and microscopes to study objects brought enormous and can include hair, fibers, glass, soil, to their laboratories. © Jones & Bartlettfeathers, Learning,pollen, dust, LLC and paint. © Jones &Early Bartlett crime Learning, labs relied almostLLC entirely on the NOT FOR SALEIn OR 1932, DISTRIBUTION with a borrowed microscope andNOT a FORlight SALEmicroscope OR DISTRIBUTIONfor examining minute details of few other pieces of basic equipment, the Federal evidence that were not visible to the naked eye. Bureau of Investigation (FBI) established its tech- This kind of a microscope offered less than 10 nical laboratory in Washington, DC. The micro- times (10×) magnification capabilities but was still scopic comparison© Jonesof fibers & and Bartlett hairs was Learning, among LLCconsidered a wonder. © Jones & Bartlett Learning, LLC the first examinationsNOT FORperformed SALE by OR this DISTRIBUTION labora- NOT FOR SALE OR DISTRIBUTION tory. Since then, forensic laboratories (including Refraction the FBI laboratory) have greatly expanded their capacity to handle trace evidence thanks to the A magnifying glass is a lens that is thicker in the development of modern analytical instruments. middle than at the edge. It makes objects appear Even© Jones with much& Bartlett more Learning,sophisticated LLC instruments larger than© Jones they are & Bartlettby refracting Learning, (bending) LLC light available,NOT FOR however, SALE forensicOR DISTRIBUTION scientists today usu- rays as NOTthey repeatedlyFOR SALE pass OR through DISTRIBUTION the air and ally begin their examination of trace evidence back through the lens. When light passes at an angle with a microscope. This chapter describes the through the interface between two transparent various types of microscopes available in forensic media (e.g., air and glass) that have different densi- © Jones & Bartlettlaboratories Learning, that are LLC used to examine hairs and© Jones ties, & an Bartlett abrupt changeLearning, in direction—that LLC is, refrac- NOT FOR SALEfibers. OR DISTRIBUTION NOT FORtion —ofSALE the ORbeam DISTRIBUTION is observed as a consequence of 84 CHAPTER 4 The Microscope and Forensic Identification of Hair, Fibers, and Paint © Jones & Bartlett Learning, LLC. NOT FOR SALE OR DISTRIBUTION. 9781449691790_CH04_FINAL.indd 84 28/10/13 9:42 AM © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE OR DISTRIBUTION FIGURE 4-1 The glass on the left shows the apparent position of a straw in water as seen by the eye. Refraction makes it appear that the straw is broken at the surface of the water. © Jones & Bartlett Learning, LLC © Jones & Bartlett Learning, LLC NOT FOR SALE OR DISTRIBUTION NOT FOR SALE