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Published byCollin Casey Modified over 8 years ago
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The Jon Benet Ramsey Case Catalyst: What were the issues with the original investigation? What went wrong?
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VIDEO What new evidence came into play in the case? How does this new Touch DNA technology work? Why is gathering as much evidence as possible important?
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Crime Scene Investigation Do you think the Ramseys should have been exonerated? Why or why not?
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Forensic Science: Fundamentals & Investigations, Chapter 2 4 Chapter 2 Crime Scene Investigation and Evidence Collection 08.18.2008 GATTACA clip
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Forensic Science: Fundamentals & Investigations, Chapter 2 5 Chapter 2 Crime Scene Investigation and Evidence Collection By the end of this chapter you will be able to: summarize Locard’s exchange principle identify four examples of trace evidence distinguish between direct and circumstantial evidence identify the type of professionals who are present at a crime scene summarize the three steps of a crime scene investigation explain the importance of securing the crime scene identify the methods by which a crime scene is documented demonstrate proper technique in collecting and packaging trace evidence describe how evidence from a crime scene is analyzed All Rights Reserved South-Western / Cengage Learning © 2009
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Forensic Science: Fundamentals & Investigations, Chapter 2 6 Vocabulary Crime scene investigation: recognize, document, and collect evidence at crime scene. Trace Evidence: small but measurable amts. Of phys./bio. material @ crime scene Direct Evidence: firsthand obs. / video camera accounts of crime Circumstantial Evidence: indirect evidence that implies fact (but doesn’t prove it)
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Forensic Science: Fundamentals & Investigations, Chapter 2 7 Principle of Exchange Dr. Edmond Locard, director of the world’s first forensic lab (1910, Lyon, France), established the idea of the exchange principle; namely that: 1. When a person comes in contact with an object or another person, a cross-transfer of physical material can occur. 2. Study of the material can determine the nature and duration of the transfer.
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Forensic Science: Fundamentals & Investigations, Chapter 2 8 Types of Evidence Statements of a witness in court would be direct evidence. Indirect or circumstantial evidence, such as a fingerprint (physical evidence) or blood or hairs (biological evidence), would imply something, and is called trace evidence.
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Forensic Science: Fundamentals & Investigations, Chapter 2 9 Types of Evidence ClassIndividual Identifies group of person/things Identifies specific person/thing
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Forensic Science: Fundamentals & Investigations, Chapter 2 10 Types of Evidence ClassIndividual Identifies group of person/things Identifies specific person/thing e.g. Blood Typee.g. fingerprint
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Forensic Science: Fundamentals & Investigations, Chapter 2 11 Types of Evidence Evidence taken from a crime scene. Direct or circumstantial evidence? Physical or biological evidence? Class or individual evidence? Explain why this would be or would not be trace evidence.
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Forensic Science: Fundamentals & Investigations, Chapter 2 12 The Crime Scene Investigation Team Who is at the crime scene? Police and possibly a district attorney. Crime scene investigators. Medical examiners. Detectives. Specialists.
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Types of Evidence bsapp.com
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Documents Hand written Hand written Type or Printed Type or Printed Authenticity? Authenticity? bsapp.com
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Glass How broken? How broken? Link a suspect to a crime scene Link a suspect to a crime scene Fingerprints Fingerprints Blood Blood bsapp.com
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Soils, Minerals, Wood, and Other Vegetative Matter. Location Location Link suspect Link suspect Trace Evidence Trace Evidence bsapp.com
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Fingerprints Mainstay of Forensics Mainstay of Forensics Who is on file? Who is on file? bsapp.com
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Hair What type? What type? How removed? How removed? Match to a person Match to a person DNA DNA bsapp.com
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Fibers Link suspect to a location or victim Link suspect to a location or victim Origin? Origin? bsapp.com
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Firearms and Ammunition Circumstances of discharge Circumstances of discharge Link to suspect Link to suspect Link to weapon Link to weapon Link to victim Link to victim bsapp.com
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Powder Residue Evidence of shooting Evidence of shooting Circumstances of shooting Circumstances of shooting Type of weapon Type of weapon bsapp.com
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Explosives & Propellants Link to suspect or victim Link to suspect or victim Origin Origin bsapp.com
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Tool Marks Match tool to scares Match tool to scares bsapp.com
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Impressions
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Drugs Type of Drug? Type of Drug? Strength? Strength? Origin? Origin? Legal? Legal? bsapp.com
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Paint Origin Origin Match Match bsapp.com
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Blood, Semen, Saliva, Organs, & other Physiological Fluids Origin Origin DNA DNA Condition Condition bsapp.com
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Forensic Science: Fundamentals & Investigations, Chapter 2 30.......... Summary.................. Summary........ Locard’s exchange principle: contact between people and objects can transfer material that can determine the nature and duration of the transfer. Evidence can be direct, indirect (circumstantial), physical, biological, class, or individual. A crime scene investigation team consists of police, detectives, crime scene investigators, medical investigators, and specialists. Numerous types of evidence depending on the crime!
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Forensic Science: Fundamentals & Investigations, Chapter 2 31.......... Reminders.................. Reminders........ Read pp.24-28 & make a mnemonic device to remember the 7 S’s.
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