David Collins Brigham Young University—Idaho
rime-time television is chock-full of drama centered on the criminal justice system. Programs such as CSI: Crime Scene Investigation, Law & Order, Criminal Minds, and Cold Case carry the viewer through stimulating, yet nearly impossible-to-solve, investigations that culminate with the evidence revealing the entire untold story behind a crime in one hour or less. In real life the collection and analysis of evidence involves painstaking care and rigorous application of scientiﬁc principles. Have you ever wondered how evidence in an actual case tells the story, what information each item of evidence holds, and how this information can be elucidated in a crime laboratory? In this chapter we will explore the world of forensic chemistry, focusing on the theory and processes of forensic analysis and showing the role that chemistry plays in criminal investigations.
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Charles D. Winters
Forensic scientists play a key role in criminal investigations. Fingerprints collected from a suspect will be compared to ﬁngerprints collected at the crime scene after being developed in the lab by a forensic scientist.
1 Introduction to Forensic Science 2 Forensic Chemistry 3 Theory of Forensic Analysis 4 Fingerprint Development 5 Presumptive Drug Analysis 6 Soil Analysis 7 Thin Layer Chromatography and Ink Analysis 8 Conclusions
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By the end of this chapter, you should be able to answer some basic questions about forensic chemistry: • • • • • What is forensic science? How is chemistry used in forensic science? What determines the value of each item of evidence? Is the analysis process for each item of evidence the same? What type of information allows for an exclusive link?
INTRODUCTION TO FORENSIC SCIENCE
Forensic science The application of science principles, techniques, and methods to the investigation of crime; the use of science to aid in the resolution of legal matters; scientiﬁc analysis for the purpose of judicial resolve. Forensic history The use of science to answer historical questions.
Forensic science applies science principles, techniques, and methods to the investigation of crime. A lesser known deﬁnition of the adjective forensic is anything argumentative or debatable. At ﬁrst, this deﬁnition of forensic may seem to have no connection with the more popular crime-solving deﬁnition—but it does. Legal truth is sought through the use of the adversarial system (rather than the scientiﬁc method), and decisions are made only after each side has been given an equal opportunity to argue all the issues at hand. When one of the issues being argued is a scientiﬁc analysis (using the scientiﬁc method) of an item of evidence, the debate that ensues over the science involved could be called forensic science. Other related deﬁnitions of forensic may include (1) the use of science to aid in the resolution of legal matters and (2) a scientiﬁc analysis for the purpose of...