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The Crime Scene

The Crime Scene. Forensic Science: Fundamentals and Investigation. The Seven S ’s of Crime Scene Investigation. S ecure the scene S eparate the witnesses S can the scene S eeing the scene S ketch the scene S earch for evidence S ecure the collected evidence. First Responding officer.

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The Crime Scene

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  1. The Crime Scene Forensic Science: Fundamentals and Investigation Bertino

  2. The Seven S’s of Crime Scene Investigation • Secure the scene • Separate the witnesses • Scan the scene • Seeing the scene • Sketch the scene • Search for evidence • Secure the collected evidence Forensic Science: Fundamentals & Investigations, Chapter 2

  3. First Responding officer • First on scene is responsible for: • Acquiring medical assistance for injured • Detaining any suspects and witness • Secure the scene to greatest extent possible • Look for points of entry and exit • Call for any needed personnel • backup or forensic investigator Forensic Science: Fundamentals & Investigations, Chapter 2

  4. Securing the scene • A perimeter needs to be set • Preserves and protects scene and evidence • May be necessary to set up multi level perimeters • Investigators should never do anything that might alter the crime scene including smoking, eating, drinking, or littering. Forensic Science: Fundamentals & Investigations, Chapter 2

  5. Multi Level Containment Forensic Science: Fundamentals & Investigations, Chapter 2

  6. The Crime Scene Investigation Team Who is at the crime scene? • Police and • District attorney (possibly) • Crime scene investigators • Medical examiners • Detectives • Specialists Forensic Science: Fundamentals & Investigations, Chapter 2

  7. Searching the Scene • The search for physical evidence at a crime scene must be thorough and systematic. • The search pattern selected will normally depend on the size and locale of the scene and the number of collectors participating in the search. • Before search begins area should be surveyed Forensic Science: Fundamentals & Investigations, Chapter 2

  8. Crime-Scene Search Patterns Forensic Science: Fundamentals & Investigations, Chapter 2

  9. Searching the crime scene • Vehicle Searches • Investigators search interior and exterior of vehicle. • The vehicle may be searched at the crime scene or at the police department or crime laboratory garage Forensic Science: Fundamentals & Investigations, Chapter 2

  10. Recording the Crime Scene • Photography, sketches, and notes are the three methods for crime-scene recording. Forensic Science: Fundamentals & Investigations, Chapter 2

  11. Crime Scene Notes • The crime scene notes should begin with: • The identity of person who contacted the investigator • Time of contact and arrival at the crime scene • Preliminary case information • Personnel present on arrival and those being contacted Forensic Science: Fundamentals & Investigations, Chapter 2

  12. Crime Notes… • Notes contain a personnel log, all observations made by the investigator, and the time observations were made. • Notes are taken in a uniform layout, concurrently as the observations are made. • Notes are written in a bound notebook in blue or black ink Forensic Science: Fundamentals & Investigations, Chapter 2

  13. Crime Scene Photography • Crime scene photographs should record the area in which the crime actually took place and all adjacent areas where important acts occurred. • The most important prerequisite for photographing a crime scene is for it to be in unaltered condition Forensic Science: Fundamentals & Investigations, Chapter 2

  14. Crime Scene Photography • Required Photographs • Overview photo • Medium range photo • Close-up photo • Close-up photo with scale Forensic Science: Fundamentals & Investigations, Chapter 2

  15. Forensic Science: Fundamentals & Investigations, Chapter 2

  16. Forensic Science: Fundamentals & Investigations, Chapter 2

  17. Forensic Science: Fundamentals & Investigations, Chapter 2

  18. Crime Scene Sketch • Clearly show the layout of a crime scene • Illustrate the relationship in space of all significant items and features • Clarify objects and features already described in notes or shown in photographs • Show measurements over long distances and topography of outdoor scenes • Depict possible paths of entry, exit, and movement through the scene Forensic Science: Fundamentals & Investigations, Chapter 2

  19. Rough Sketch • A rough sketch is created at the crime scene and contains an accurate depiction of the dimensions of the scene and shows the location of all pertinent objects and features. Forensic Science: Fundamentals & Investigations, Chapter 2

  20. Crime-Scene Sketch Form Forensic Science: Fundamentals & Investigations, Chapter 2

  21. Forensic Science: Fundamentals & Investigations, Chapter 2

  22. Forensic Science: Fundamentals & Investigations, Chapter 2

  23. Search and Seizure • The removal of any evidence from a person or from the scene of a crime must be done in conformity with Fourth Amendment privileges: Forensic Science: Fundamentals & Investigations, Chapter 2

  24. SCOTUS Says…. • Search and seizure without a court-approved warrant is justified in four cases: • The existence of emergency circumstances • The need to prevent the immediate loss or destruction of evidence • A search of a person and property within the immediate control of the person provided it is made incident to a lawful arrest • A search made by consent of the parties involved Forensic Science: Fundamentals & Investigations, Chapter 2

  25. Search and Seizure Cases • In the case of Mincey v. Arizona, the Court dealt with the legality of a four-day search at a homicide scene and determined that the evidence was illegally seized because a warrant was never issued and the circumstances of the case did not justify a warrantless search. Forensic Science: Fundamentals & Investigations, Chapter 2

  26. More Cases… • In Michigan v. Tyler, fire destroyed a business establishment leased by Loren Tyler and a business partner. The court decided that evidence obtained from the initial search was legally seized, but evidence obtained from searches 4, 7, and 24 days after the incident were illegally seized. Forensic Science: Fundamentals & Investigations, Chapter 2

  27. Types of Evidence Direct evidence Testimony by a witness about what that witness saw, heard, or did Forensic Science: Fundamentals & Investigations, Chapter 2

  28. Types of Evidence Circumstantialevidence • also called Indirect • trace evidence Physical evidence • e.g., fingerprints Biological evidence • e.g., blood or hairs Forensic Science: Fundamentals & Investigations, Chapter 2

  29. Collecting Evidence • Often, many items of evidence are clearly visible but others may be detected only through examination at the crime laboratory. Forensic Science: Fundamentals & Investigations, Chapter 2

  30. Collection… • Investigators handle and process physical evidence in a way that prevents changes to the evidence through contamination, breakage, evaporation, accidental scratching or bending, or through improper or careless packaging. • Need to avoid contamination at all costs. Forensic Science: Fundamentals & Investigations, Chapter 2

  31. Packaging the evidence • Crease a clean paper and place evidence in the X position • Fold in the left and right sides, and then fold in the top and bottom • Put the bindle into a plastic or paper evidence bag affixing a seal over the opening • Write your name on the seal Forensic Science: Fundamentals & Investigations, Chapter 2

  32. Evidence ID Forms Forensic Science: Fundamentals & Investigations, Chapter 2

  33. Chain of Custody Maintaining a chain of custody log is essential to present credible evidence in court Forensic Science: Fundamentals & Investigations, Chapter 2

  34. Chain of Custody (cont’d.) • Bag the evidenceAdd identification Seal itSign it across the sealed edge • Sign over to a lab technician Open bag on non-sealed edge • Return items to the evidence bagSeal evidence bag in another bagSign the evidence log Forensic Science: Fundamentals & Investigations, Chapter 2

  35. Reference Samples • Standard/Reference Sample • Physical evidence whose origin is known, such as blood or hair from a suspect, that can be compared to crime-scene evidence. Forensic Science: Fundamentals & Investigations, Chapter 2

  36. Leaving the Scene • The lead investigator decides when all pertinent evidence has been recorded and collected • A final survey is undertaken to visually review the scene and collect all evidence and equipment Forensic Science: Fundamentals & Investigations, Chapter 2

  37. Submitting the Evidence • Must complete an evidence submission form • Need to provide case information • Which tests are to be run • Lab Technician can run more tests than indicated if feel will further the case Forensic Science: Fundamentals & Investigations, Chapter 2

  38. Analyze the Evidence • Facts result from collected evidence processed by the forensic lab • Lead detective aims to see how facts fit into the crime scenario Forensic Science: Fundamentals & Investigations, Chapter 2

  39. Analyze the Evidence Lab results can: • Show reliability of witness accounts • Establish the identity of suspects or victims • Show suspects to be innocent or link them with a scene or victim Forensic Science: Fundamentals & Investigations, Chapter 2

  40. Crime Scene Reconstruction Crime scene reconstruction involves: • Forming a hypothesis of the sequence of events • From before the crime was committed through its commission Forensic Science: Fundamentals & Investigations, Chapter 2

  41. Staged Crime Scenes When lab results don’t match up with the testimony of witnesses Common examples: • Staging a fire—to cover bankruptcy • Staging a suicide—to cover a murder • Staging a burglary—to collect insurance money Forensic Science: Fundamentals & Investigations, Chapter 2

  42. Staged Crime Scenes Was the crime scene staged? Consider: • Does the type of wound match the weapon? • Could the wound be easily self-inflicted? • What were the mood and actions of the victim before the event? • What were the mood and actions of the suspect before the event? Forensic Science: Fundamentals & Investigations, Chapter 2

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