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Chapter 2

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Chapter 2

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  1. Chapter 2 The Scene of the Crime

  2. Mock Crime Scene- Video Clip

  3. Fundamental Practices at Crime Scenes • Secure and Isolate Crime Scene • Record Crime Scene • Photograph Crime Scene • Sketch Crime Scene • Maintain Detailed Notes • Conduct Systematic Search for Evidence • Collect and Package Evidence • Maintain Chain of Custody • Obtain Standard/Reference Samples • Submit Evidence to Library • Maintain Safety at Crime Scene

  4. Securing the Scene • Responsibility: 1st officer to arrive (first responder) • Medical assistance provided if needed • EVERY person entering scene is a potential destroyer of evidence (intentionally or accidentally) • Prevent entry by unauthorized personnel • Ropes, tape, barricades • Record maintained of anyone entering/leaving crime scene

  5. Separating the Witness • Preventing witnesses from talking. • Allows for comparison of their accounts • Helps prevent them from working together to create a story. • Ask them questions about the incident such as: • Where were you when you observed the crime? • What did you see happen?

  6. Record/Scan Crime Scene • Lead investigator evaluates the area. • Limited time for processing scene before it gets disrupted by various personnel • Boundaries of crime scene determined • Primary crime scene • Secondary crime scene • Initial walk-through conducted by lead investigator • Strategy developed to process scene • Photograph and/or sketch scene • Take detailed notes

  7. Seeing the Scene • Photos taken without altering the scene or moving objects • If anything gets moved, photos may not be admissible in court as evidence. • Detailed notes taken to override this issue.

  8. Seeing the Scene • ALL angles of crime scene must be photographed • All adjacent areas as well • All points of entry/exit • If scene includes body, pictures of the position and location relative to entire scene must be taken • Close-ups of injuries and weapons • Once body is removed, the surface under body must be photographed • Each piece of evidence must be photographed in its original location next to a ruler or other measuring device AND a number I.D. card • Video recorders are also used, but have not replaced still photographs

  9. Sketching the Scene • Once photos are taken, the crime-scene investigator will complete a rough sketch of the scene. • Rough sketch uses geometric shapes, letters and numbers. • Finished sketch is created with much more care and detail. • Computer aided drafting (CAD) can be employed to do this.

  10. Rough Sketch

  11. Finished Sketch – Hand Drawn

  12. Finished Sketch (CAD)

  13. Maintain Detailed Notes • Must be a constant activity • Must include a written description of scene and locations of all objects of all evidence

  14. Searching For Evidence • Searches must be conducted with extreme care and have to be thorough. • Hap-hazard searches  clues missed or lost. • Systematic searches, using specific patterns are used. • Critical areas of the scene may vacuumed with portable vacuum cleaners equipped with special filters. • The search for evidence extends beyond crime scene to the autopsy • Medical examiner contributes results of toxicology and pathology examinations

  15. Systematic Search Patterns • Search patterns include: • Spiral searches (outward & inward) • Quadrant method aka Grid and Zone • Parallel search

  16. Spiral Search

  17. Also called the Quadrant Method Grid and Zone

  18. Parallel

  19. Securing and Collecting Evidence • Evidence must be collected and packaged correctly so it does not change from the time it was collected to the time it is processed by the crime lab. • Ex: evaporation, contamination, breakage, etc. • Each piece of evidence is packaged separately. • Evidence must be handled with forceps (gloved hands only) or similar tools

  20. Securing and Collecting Evidence Evidence collecting includes: • Plastic pill bottles, manila envelopes, glass bottles etc. • for storing hair, fibers, glass and various small or “trace” evidence. • Paper- “druggist fold” or bindle • Way to store trace evidence.

  21. Chain of Custody • List must be maintained of all persons who had possession of a particular item of evidence. • Without it- Authenticity and integrity of the evidence are in question and it may not be admissible in court. • Every time evidence container is opened and closed it must be sealed with a label containing • examiner’s name, date and location of the item. • If the evidence is moved to another location/lab, the date of this transfer must also appear on the label. • Complete record of all persons in touch with the evidence is maintained and these persons may be summoned to court to testify.

  22. Reference Samples • All evidence must be compared to a known (standard/reference) sample • For example, blood-stained evidence must be accompanied by blood or buccal samples from both the victim as well as the suspect(s) • Same is true with hair, fibers, soil, etc.

  23. Questions: Use Chapter 2 Pages 56-59 to answer the following questions: • Describe the procedures for collecting and packaging evidence. • What is a “druggist fold” (or bindle) used for? • Identify all the tools used for evidence collection. • How are bloodstained materials, charred materials, and clothing collected and preserved? • Create a druggist fold using a sheet of paper. Refer to the worksheet for instructions. Turn this in with your assignment.

  24. Evidence Collection • Evidence must be collected and packaged correctly to prevent change from the time of collection to the time of processing by the crime lab. • Changes- evaporation, contamination, breakage, etc. • Each piece of evidence MUST be packaged separately. • Evidence MUST be handled with forceps (gloved hands only) or similar tools

  25. Evidence Collection • Blood-soaked clothing must NOT be stored in air-tight containers • trapped moisture may cause the growth of mildew and mold and destroy the blood. • All clothing MUST be air-dried and individually stored in paper bags. • Charred clothing or debris, MUST be stored in air-tight containers preventing evaporation of petroleum residues.

  26. Questions • Why would investigators remove a small paint chip from the vehicle belonging to a suspect of a hit-and-run case? It can act as a reference sample/standard to be compared to paint recovered at the scene.

  27. Submitting Evidence to the Lab • Delivered personally or by mail • Exceptions to mail delivery: explosive, certain chemicals, live ammunition, etc. • Receiving lab must get a case history or any such report along with the evidence. • Clear request of type of examination for each piece of evidence included. • Analysts may perform other tests if necessary • Include completed Evidence submission form and list of all evidence items.

  28. Mincey vs. Arizona (1978) **See Module 10 Packet** • Supreme Court ruled that law enforcement officials • May enter in search of victims and provide aid when needed. • Limited to realistic areas (ex: not in a shoebox) • May search for perpetrator under same guidelines.

  29. Mincey vs. Arizona (1978) • May seize evidence in plain view as they search for victims and perpetrators. • Restrictions: • Seized item must easily be determined to be relevant without examination. • Plain view seizures only conducted when evidence may be lost, destroyed, or altered.

  30. What is the 4th Amendment?

  31. Legal Considerations at Crime Scenes • Removal of any person/evidence from crime scenes must be done in conformity with Fourth Amendment privileges: • The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

  32. Legal Considerations at Crime Scenes • Search warrants are REQUIRED. A warrantless search can only be conducted under the following circumstances: • Existence of an emergency • To prevent immediate loss or destruction of evidence • Search of a person or property of the person during his arrest • Search and seizure with the consent of the persons involved

  33. O.J. Simpson • Use the Crime Museum’s article regarding the collection and use of evidence in the O.J. Simpson trial to answer the following questions. • Identify some of the key pieces of evidence found at the crime scene. • Describe why many critical pieces of evidence were not admissible in court. Provide at least three examples from the text to support your answer.

  34. Review Activity: Sketching the Scene • Use Figure 2-3 (Diagram of a crime scene) and your textbook (pg. 48-51), to answer the following questions: • Identify the important elements of a detailed rough sketch of a crime scene. • Differentiate between a rough sketch and a finished sketch. • Do you think it is important to document the location from which photographs were taken? Explain your answer.