NCJ Number
80806
Date Published
1980
Length
298 pages
Annotation
This criminalistics manual is designed as an introduction to analyses performed in a forensic laboratory and is intended for criminal justice and general science students. It presents 38 experiments which show the significance of physical evidence from crime scenes, demonstrate how physical evidence is analyzed according to standard laboratory practices, and train students in the rules of evidence preservation.
Abstract
Procedures are described with terminology comprehensible to nonscience students, although advanced-level experiments are included for science oriented students. Experiments illustrate the metric system, measurement of the density of glass fragments, use of the microscope, measurement of the refractive index of glass fragments, soil analysis, measurement of the density of glass by flotation and density gradient columns, and measurement of powder residues on fabric. Other experiments cover identifying and typing blood, typing dried blood stains, fingerprinting, comparing tool marks and casting, restoring serial numbers on metal, examining hair by microscopy, identifying textile fibers, qualitatively measuring marijuana, identifying general classes of drugs, and identifying drugs and poisons by infrared spectrography. Also covered are measurement of salicylates in blood by fluorometry, measurement of quinine in urine by fluorometry, measurement of salicylates in blood by visible spectroscopy, use of the breathalyzer, analysis of blood alcohol by gas chromatography using a thermal conductivity detector and a flame ionization detector, analysis of ink by paper chromatography, separation of ink dyes using thin-layer chromatography, determination of lipstick dyes by thin-layer chromatography, identification of human seminal stains by human prostatic acid phospatase, immunological identification of human semen, and arson detection by recovery of flammable liquids or by determination of gasoline dyes using thin-layer chromatography. Additional experiments encompass using spot tests and thin-layer chromatography for determination of explosive residues; identifying metal residues on hands from guns, knives, or other metal weapons; determining chemical elements in materials using emission spectroscopy; identifying heavy metal poisons by atomic absorption spectroscopy; using the comparison microscope; and analyzing a burglary scene. Each section contains a list of equipment or reagents needed, a description of the method, a data sheet, and a bibliography. Illustrations are supplied.