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Chapter 3

Chapter 3. The Crime Scene. Vocabulary. Crime Scene Modus operandi Chain of custody. Individual vs. Class Evidence. Individual Can be associated with a high rate f certainty DNA Fingerprint ridge pattern Class Associated with a group and not an individual Blood type

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Chapter 3

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  1. Chapter 3 The Crime Scene

  2. Vocabulary • Crime Scene • Modus operandi • Chain of custody

  3. Individual vs. Class Evidence • Individual • Can be associated with a high rate f certainty • DNA • Fingerprint ridge pattern • Class • Associated with a group and not an individual • Blood type • Fingerprint pattern

  4. Blood Hair, paint, fibers DNA Body fluids Body tissues Drugs Documents Fingerprints Fire and explosives residue Ammunition Glass Tool marks Soil, plants Tire tracks Impressions Shoe prints Types of Physical Evidence

  5. The Backbone • Crime laboratories rely on physical evidence • Physical evidence is any and all objects that can establish that a crime has been committed • It is also all evidence that can provide a link between the crime and its victim or the crime and perpetrator

  6. In order to achieve optimum value in a criminal investigation the physical evidence must be collected selectively. • The collector’s knowledge of the crime lab’s techniques, capabilities and limitations are the factors involved in this selection process.

  7. Crime Scene Protection "Oh, how simple it would all have been had I been here before they came like a herd of buffalo and wallowed all over it." -A. Conan Doyle, The Boscombe Valley Mystery, 1892.

  8. Forensic science begins at the crime scene. • Information collected at the crime scene must be used later in reconstructing the sequence of events or the modus operandi, and the motive for the crime. • Not all crime scenes require retrieval of physical evidence. • The reality is that the gathering of physical evidence is restricted to serious crimes.

  9. Secure and Isolate the Crime Scene • The first officer on the scene must preserve and protect the crime scene area. • First priority should be given to get medical assistance if needed and apprehending the perpetrator.

  10. Ropes or barricades are set up. • Limit the access to the crime scene. • Every individual who enters the crime scene is a potential destroyer of physical evidence. • If there has been a death, the medical examiner should note the body’s condition, and estimate the time of death. • Oblique lighting is used indoors on hard surfaces.

  11. Evaluation • Secure the scene • Determine the boundaries of the scene • Establish the perp’s path of entry and exit • Document and photograph the obvious items • Initial walk-through • Overview of the situation • Develop a strategy for systematic examination and documentation of the entire crime scene Observation

  12. Why Record the Scene? • Records will be useful during the investigation. • Required for presentation at the trial • Document the crime site condition • Delineate the location of any physical evidence

  13. Crime Scene Reporting • Photography • Sketches • Notes Ideally all three should be used, however, many times the utilization of photography is limited due to personnel and monetary limitations

  14. Notes • Forces investigators to be observant. • Should be complete, thorough, written clearly, and legibly • Detail step by step every action taken and in what order the steps were taken. • Measure the scene and refer to these measurements in describing all evidence and where the evidence were found.

  15. Notes • Include date and time • Description of location including weather and environmental conditions. • Description of the crime, the location of the evidence in relation to other key points. • The names of the persons involved, including authorized personnel, witnesses, and victims.

  16. Notes • Make a written description of the physical evidence, its location, its time of discovery, and packaging. • May wish to use a tape-recording device and then transcribe latter.

  17. Photography • Crime Scene must be in an unaltered state. • No objects should be moved until photographed from all angles. • If evidence has been removed or moved prior to photography, this must be noted in the report.

  18. Photography • If the crime scene includes a body: • Show the bodies position • Location relative to the entire crime scene • Close-up photos of injuries and weapons are necessary • After the body is removed, photograph the surface that was underneath the body.

  19. Sketches • Rough Sketch • Draft representation of all essential information and measurements at a crime scene

  20. Create a legend. The sketch legend explains all symbols, numbers, or letters used to identify objects on the sketch. Military symbols are used where practical. • Indicate compass direction. The compass direction of north should be indicated by an arrow and the letter "N."

  21. Needed Materials 1. Paper (Notepad & Sketchpad) 2. Mechanical Pencils 3. Grease Pencil 4. Drafting Tape 5. 250 foot Steel Tape 6. 35mm Camera 7. Index Cards 8. Compass 9. Pocket Tape Recorder

  22. https:/.../cgi-bin/ atdl.dll/accp/mp2004/le1.htm

  23. Finished sketch is drawn with care and concern for aesthetic appearance. • Templates • Drafting tools • Drawn to scale • Skilled individual

  24. Must reflect the information contained within the rough sketch in order to be used as evidence in the courtroom. Computer aided drafting

  25. Diagram from "GreenKil" case, 1979, Jim Ballance http://www.ballanceart.com/forensicSCENESKCH.html

  26. Hudson Double Homicide Case http://www.ballanceart.com/forensicSCENESKCH.html

  27. Systematic Search • Thorough and systematic • No pertinent evidence can be overlooked. This will insure a factual and unbiased reconstruction of the crime. • Not necessary to have a forensic scientist present, unless, it is a major crime. • Advisable to have one person supervising and coordinating the collection of the evidence. • Physical evidence can be anything from massive objects to microscopic traces.

  28. Systematic Search • Collect possible carriers of trace evidence: Clothing • Each piece of clothing must be wrapped separately. • Areas of the crime scene must be vacuumed so that the sweepings can be submitted to the lab for analysis. • Different sweepings from different areas must be packaged separately. • Fingernail scrapings from those individuals who were in contact might contain minute fragments of evidence.

  29. Systematic Search • From the autopsy room • Cause and manner of death • Tissues and organs are retained for pathological and toxicological examinations • The following items are collected and sent to the forensic lab • Victim’s clothing • Fingernail scrapings • Head and pubic hairs • Blood (DNA Typing) • Vaginal, anal, and oral swaps (Sex-related crimes) • Recovered bullets • Hand swabs from shooting victims (gunshot residue analysis)

  30. Collection and packaging of the Physical Evidence • Important to prevent • Contamination • Breakage • Evaporation • Accidental scratching • Bending • Loss • Through improper or careless packaging

  31. Collection and packaging of the Physical Evidence • Each different item or similar items collected at different locations must be placed in separate containers. Packaging evidence separately prevents damage through contact and prevents cross-contamination.

  32. Package materials • Forceps or similar tools • Unbreakable plastic pill bottles with pressure lids • Hairs • Glass • Fibers • Small trace evidence • Manila envelopes, screw-cap glass vials or cardboard pillboxes

  33. Package materials • Folded paper using the “druggist fold” • Bloodstained materials are not stored in airtight containers due to accumulation of moisture. They are stored in: • Wrapping paper • Manila envelopes • Paper bags

  34. Package materials • Clothing are to be air-dried and placed in separate paper bags • Charred debris must be sealed in an airtight container to prevent the evaporation pf volatile petroleum residues

  35. Obtain Controls • Known standard is used for comparison of : • Soil • Blood • Glass • Hair • Fibers • For example: bloodstained evidence must be accompanied by whole blood or buccal swab control • Hit-and-run incident might require the removal of control paint from a suspect vehicle

  36. Chain of Custody • Continuity of possession must be established if evidence is to be presented in the courtroom as an exhibit.

  37. Chain of Custody • Standard procedures in recording the location of the evidence, marking the evidence for identification, and properly completing evidence submission forms for lab analysis must be maintained. • Every person that handled the evidence or examined it must be accounted for.

  38. Submit the Evidence • Personal delivery • Mail shipment • Restricted materials • Chemicals • Live ammunition • explosives

  39. Evidence Submission Form http://www.ganet.org/gbi/pdfs/submiss.pdf.

  40. Warrentless Searches • Emergency Response • When officers hear a cry for help, they can enter a building in response. If law enforcement agents believe that a child is being abused or is in other immediate danger, they can enter the premises to rescue her. • http://www.lawcollective.org/article.php?id=105id=105

  41. Warrentless Searches • Automobile Searches • If you’re arrested in a car, the officers can search the passenger compartment, because that’s the area under your immediate control. Whether or not anyone’s been arrested, if law enforcement agents have probable cause1 to believe that your vehicle contains proof of a crime, they can search it without a warrant—and open any container in the car that might hold the items they’re seeking. If your car is impounded for any reason, even for just being in a tow-away zone, the officers can search the whole vehicle, including the trunk. http://www.lawcollective.org/article.php?id=105id=105

  42. Warrentless Searches • Students at Public Schools • On school grounds, school officials can search a student and the belongings she’s carrying, if they have “reasonable suspicion” that the student has violated the law or a school rule. Reasonable suspicion is a lower standard than probable cause.2 • The U.S. Supreme Court hasn’t yet analyzed whether a student has a right to privacy in her locker or desk. Various lower courts have produced conflicting opinions. Under the circumstances, a sensible student would not want to keep her most private possessions at school. http://www.lawcollective.org/article.php?id=105id=105

  43. Warrentless Searches • Drug Testing • The courts sometimes find drug testing constitutional. High school students can be required to submit to random drug testing in order to engage in sports, band, chorus, or academic competitions. Employees in certain high-risk jobs can be required to drug test (such as railroad workers who’ve been in an accident or broken safety rules; or applicants for U.S. Customs jobs that relate to drug-smuggling or that involve carrying a gun). http://www.lawcollective.org/article.php?id=105id=105

  44. When time and circumstances permit, obtain a search warrant before investigating and retrieving physical evidence at the crime scene.

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