Ch. 12: The Forensics Laboratory

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Ch. 12 The Forensics Laboratory
http//picsicio.us/keyword/csi20forensics20lab/
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I. Forensics Lab

• Must be accredited and are monitored to keep this
  accreditation
• Quality assurance program
• 1. Necessary to meet accreditation requirements
• 2. Includes education of staff, peer review of
  results, evidence
• handling, lab security, proficiency tests, etc.
• (Proficiency tests simulated forensic cases
  produced
• internally or by outside testing agency)
• Director of lab criminalist
• Association with a law enforcement agency helps
  with the free EXCHANGE of info and access to CS
  and physical evidence

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II. Criminalist

• A. Difference between forensics and
  criminalistics
• 1. forensics more general
• --Can apply to any of scientific
  disciplines
• (ex. anthropology and odontology)
• 2. Criminalist a scientist who applies the
  principles of primarily biology, physics, and
  chemistry to evidence analysis AND is also
  trained in crime scene investigation and
  reconstruction

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II. Criminalist (continued)

• B. Role of criminalist
• 1. Provide investigative leads . . . .How?
• a. Through scientific evaluation of
  physical evidence and a crime scene
  reconstruction
• b. Report results and conclusions of the
  scientific evaluations

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II. Criminalist (continued) B. Role of a
criminalist

• To act as an . . .
• a. Investigatorasking questions, communicating
  with police
• b. Educatoreducate individuals at all levels of
  a case (i.e. law enforcement officers, CSI,
  attorneys, judges, etc.)expert testimony
• c. Studentmust stay current and continue to
  learn because of advancing technology and trends

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III. Classifying and using physical evidence in
a lab

• A. Reconstruction Evidence
• 1. Provides info about events preceding,
  occurring during, and after a crime
• 2. Three commonly used tools to help locate
  reconstruction evidence
• a. Luminol chemical that reacts with minutes
  quantities of blood
•  

After
Before
http//science.howstuffworks.com/luminol1.htm
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III. Classifying and using physical evidence in
a lab

• A. Reconstruction Evidence
• 1. Provides info about events preceding,
  occurring during, and after a crime
• 2. Three commonly used tools to help locate
  reconstruction evidence
• a. Luminol chemical that reacts with minutes
  quantities of blood
• b. Alternate light source detects body
  fluid stains,
• fibers, other compounds that
• fluoresce under various
• wavelengths of light
•   c. Blood stain analysis

http//www.knoxandassociates.com/evidence.php
http//science.marshall.edu/murraye/Blood20Spatte
r20Lab.html
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• Classifying and using physical evidence in a lab
• (continued)

• B. Associative Evidence
• 1. Is evidence that can be used to
  associate or dissociate a
• suspect to a crime
• 2. Further subdivided into . . .
• Individual or identification evidence
• evidence is linked to a particular source
• Ex. fingerprints, DNA profiles, some
  impressions, and fracture matches
• b. Class characteristic evidence
• evidence is associated with a group and
  not considered unique
• --Conclusions regarding class characteristic
  evidence are limited

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Activity

• CSI Web Adventures

• http//forensics.rice.edu/