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FS Fall Final Review. Ch 1 and 2 observations and CSI. What factors affect our observations? How does the brain process information? How could you become a better eyewitness?.
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Ch 1 and 2observations and CSI • What factors affect our observations? • How does the brain process information? • How could you become a better eyewitness?
Forensic investigators recognize, document, collect, and organize evidence left at the scene of a crime. Factors that affect observational skills such as emotion, perception and recall,time of day, level of interest, number of people…
Your brain… • Filters (what is important, what you notice, your level of interest, who you are with, where you are….) • Fills in gaps (you may think you saw it…) • Applies previous knowledge (you sort out issues based on what you know)
Who does what? • Who secures the scene and separates witnesses? • Who takes measurements and notes location of evidence • Who interviews the witnesses
Locard • Every contact leaves a trace • Duration • Intensity • Materials used
Fingerprints • Alphonse Bertillion • Anthropometry-use of body measurements for identification • Francis Galton-suggested 3 categories-Arches, loops and whorls • 1999 – US v. Byron C. Mitchell-case that provided 3 principles of fprint • 1. unique • 2. unchanging • 3. can be used to ID individuals
Kinds of Crime Scene Prints Patent /Visible prints – made by fingers touching a surface after ridges have been in contact with a colored materials (blood, paint, etc.) Plastic Prints – ridge impressions left on a soft material (putty, wax, soap or dust) Latent/invisible prints – caused by the transfer of perspiration/oils on finger ridges to the surface of an object
Identify each fingerprint pattern. ? A B Right Hand Left Hand C Right Hand E D Right Hand Left Hand
What Can be learned from tire impressions? • What type of impression is shown?