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 Jon Benet Ramsey Case:  House not searched for 7 hours because assumption was that it was a kidnapping  Only the girl’s bedroom was sealed initially.

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Presentation on theme: " Jon Benet Ramsey Case:  House not searched for 7 hours because assumption was that it was a kidnapping  Only the girl’s bedroom was sealed initially."— Presentation transcript:

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2  Jon Benet Ramsey Case:  House not searched for 7 hours because assumption was that it was a kidnapping  Only the girl’s bedroom was sealed initially  Father found the body in the basement, wrapped her in a blanket and carried her upstairs  After body was found, people allowed to move about freely in house  House was cleaned

3  Locard’s Exchange Principle – A) when a person comes into contact with an object or another person, a cross-transfer of physical evidence can occur.  B) the intensity, duration and nature of the materials in contact determine the extent of the transfer.

4  Animal or human hair  Fingerprints  Soil or plant material (pollen)  Body fluids like mucus, semen, saliva, blood  Broken glass/paint chips/chemicals  Fiber from clothing

5  Police officers – usually first to arrive  CSI’s – document crime scene in detail/collect physical evidence…include recorders for the data, sketch artists, photographers, evidence collectors  Medical Examiner – (coroner) to determine cause of death  Detectives – interview witnesses, talk to CSI’s about evidence  Specialists – entomologists, scientists, psychologists

6  Direct:  Firsthand observations (eyewitness accounts, police dashboard cameras); confessions  Circumstantial:  Indirect evidence that can imply a fact but doesn’t directly prove it  Can be either physical or biological  Trace evidence is an example

7  Physical: Impressions from fingerprints, footprints, shoe prints, tire impressions, tool marks, fibers, weapons, bullets, and shell casings  Biological: body fluids, hair, plant parts and natural fibers

8  Class evidence: narrows identity to a group of people (blood group for example)  Individual evidence: narrows identity to a single person/thing

9  1. Securing the Scene  Responsibility of the first responder  Safety of everyone in vicinity is top priority  Evidence preservation is second priority 2. Separating the Witnesses  Avoids collusion  Questions that should be asked include:

10  A) When did the crime occur?  B) Who called in the crime?  C) Who is the victim?  D) Can the perpetrator be identified?  E) What did you see happen?  F) Where were you when you observed the crime scene?

11  3. Scanning the Scene  Primary crime scene  Secondary crime scene  4. Seeing the Scene  CSI’s need to see the scene  Photos with and w/out rulers should be taken  Triangulation of stationary objects should be included for reference points

12  5. Sketching the Scene  Position of body (if any) and any other evidence  Should be measured from 2 immovable landmarks  North should be labeled and a scale should be provided  Positions of furniture, doors (inside), shrubs, trees (outside) should be included

13  6. Searching for Evidence  Spiral, grid, linear or quadrant patterns should be used  7. Securing and Collecting Evidence  Proper packaging, sealing and labeling is vital  Liquid/arson remains in airtight/unbreakable containers  Biological evidence in breathable containers so it can dry out  Must include a evidence log and chain of custody

14  Evidence log:  case number  Item inventory number  Description of evidence  Name of suspect  Name of victim  Date/time of recovery  Signature of person recovering the evidence  Signature of any witnesses present during collection

15  Chain of custody:  Indicates every person who has handled the evidence  Log must be attached to packaging

16  After evidence has dried, it is packed in a paper bindle (aka druggist’s fold)  Then it can be put into a plastic or paper container, labeled with evidence tag, sealed and taped with the collector’s signature across the taped edge.  Control samples must also be obtained from the victim for exclusion purposes.

17  Essential to maintain  Original collector: bags evidence properly, labels it properly, seals it and signs the sealed edge.  Next person to receive evidence signs that they received it (lab technician for example); lab tech opens sealed container at a location other than the sealed edge; after examination, tech repackages, signs log and reseals with new tape/signature.

18  Importance of Chain of Custody Importance of Chain of Custody

19  Done in forensic labs – the largest is the FBI crime lab  Forensic lab technicians are specialists – unlike what you see on tv  Results sent to lead detective who then attempts to reconstruct the crime scene

20  Involves forming a hypothesis about what happened before/during/after the crime  Witness accounts and forensic evidence are used to form the hypothesis  So what happens if the evidence doesn’t match the witness statements?

21  1. Arson – fire set to cover up another crime  2. Suicide/murder – victim murdered/stage set to appear as a suicide  3. Burglary – staged to collect insurance money

22  Initially treat all death investigations as homicides  Do the wounds match the weapon used?  Could the wounds be easily self-inflicted?  Profile the victim via interviews with family/friends  Corroborate statements with evidential facts.  Reconstruct the event – does it make sense?

23  http://www.practicalhomicide.com/Research /staging.htm http://www.practicalhomicide.com/Research /staging.htm


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