1. Forensic Science: Fundamentals & Investigations, Chapter 2 1 Chapter 2 Crime Scene Investigation and Evidence Collection By the end of this chapter you will be able to: summarize Locard’s exchange principle identify four examples of trace evidence distinguish between direct and circumstantial evidence identify the type of professionals who are present at a crime scene summarize the three steps of a crime scene investigation explain the importance of securing the crime scene identify the methods by which a crime scene is documented demonstrate proper technique in collecting and packaging trace evidence describe how evidence from a crime scene is analyzed All Rights Reserved South-Western / Cengage Learning © 2009

2. Forensic Science: Fundamentals & Investigations, Chapter 2 2 Principle of Exchange Dr. Edmond Locard, director of the world’s first forensic lab (1910, Lyon, France), established the idea of the exchange principle; namely that: 1. When a person comes in contact with an object or another person, a cross-transfer of physical material can occur. 2. Study of the material can determine the nature and duration of the transfer.

3. Forensic Science: Fundamentals & Investigations, Chapter 2 3 Types of Evidence Statements of a witness in court would be direct evidence. Indirect or circumstantial evidence, such as a fingerprint (physical evidence) or blood or hairs (biological evidence), would imply something, and is called trace evidence.

4. Forensic Science: Fundamentals & Investigations, Chapter 2 4 Common types of trace evidence: Hair on clothes or rugs Fingerprints Soil Drop of blood Paint chips Broken Glass Fibers

5. Forensic Science: Fundamentals & Investigations, Chapter 2 5 Circumstantial Evidence Indirect evidence Implies a fact, but does not prove it Physical types? Biological?

6. MORE Evidence Categories:  Class evidence - narrows an identity to a groups of persons or things; ex. Blood type, hair color…  Individual evidence - evidence belonging to one person or thing; ex. Fingerprints or DNA Forensic Science: Fundamentals & Investigations, Chapter 2 6

7. 7 Class vs. Individual Evidence  The large piece of glass fits exactly to the bottle; it is individual evidence.  These fibers are class evidence; there is no way to determine if they came from this garment.

8. Forensic Science: Fundamentals & Investigations, Chapter 2 8 Types of Evidence This evidence was taken from a crime scene. Is it Direct or circumstantial evidence? Physical or biological evidence? Class or individual evidence? Explain why this would be or would not be trace evidence.

9. Forensic Science: Fundamentals & Investigations, Chapter 2 9 The Crime Scene Investigation Team Who is at the crime scene? Police (first to arrive) and possibly a district attorney (search warrant). Crime scene investigators. Medical examiners. Detectives. Specialists.

10. Forensic Science: Fundamentals & Investigations, Chapter 2 10 The Medical Examiner and the Coroner  A medical examiner is a medical doctor, usually a pathologist and is appointed by the governing body of the area. There are 400 forensic pathologists throughout the U.S.  A coroner is an elected official who usually has no special medical training. In four states, the coroner is a medical doctor.

11. Forensic Science: Fundamentals & Investigations, Chapter 2 11 Goals of crime-scene investigation: Recognize evidence Document evidence Collect evidence Solving the crime depends on piecing the evidence together in order to form a picture of what occurred at the crime scene

12. Forensic Science: Fundamentals & Investigations, Chapter 2 12 The Seven S’s of Crime Scene Investigation 1. Secure the scene. 2. Separate the witnesses. 3. Scan the scene. 4. See to it that the crime scene examiners receive overall and close up photos with and without measuring rulers. 5. Sketch the scene. 6. Search for evidence. 7. Secure the collected evidence.

13. Forensic Science: Fundamentals & Investigations, Chapter 2 13 Packaging the evidence 1. Crease a clean paper and place the evidence in the X position (as shown above). 2. Fold in the left and right sides, and then fold in the top and bottom. 3. Put the bindle into a plastic or paper evidence bag affixing a seal over the opening. 4. Write your name on the seal.

14. 14 Practice makes perfect… Fold your own bindle!!! Use a white piece of paper and seal it up!!!

15. Things to know: Liquids and arsons stored in airtight containers Biological evidence is stored in breathable containers so it can dry without mold Control samples should be collected, if possible, for analysis at the lab Why should samples from the victim be collected? Forensic Science: Fundamentals & Investigations, Chapter 2 15

16. Forensic Science: Fundamentals & Investigations, Chapter 2 16 Chain of Custody In order to present credible evidence in court, a chain of custody log is essential. 1. A person bags the evidence, marks it for identification, seals it, and signs it across the sealed edge (above, left). 2. It is signed over to a technician in a lab for analysis who opens it, but not on the sealed edge. 3. After analysis, the technician puts it back in the evidence bag, seals it in another bag, and signs the evidence log (above, right).

17. Forensic Science: Fundamentals & Investigations, Chapter 2 17 Analyze the Evidence The facts of the case are determined when the forensic lab processes all the collected evidence. The lab then sends the results to the lead detective who aims to see how it all fits into the crime scenario.

18. Forensic Science: Fundamentals & Investigations, Chapter 2 18 Analyze the Evidence The lab results can: Show how reliable are any witness accounts. Establish the identity of suspects or victims. Show suspects to be innocent or link them with a scene or victim.

19. Forensic Science: Fundamentals & Investigations, Chapter 2 19...... Summary to this point... Locard’s exchange principle: contact between people and objects can transfer material that can determine the nature and duration of the transfer. Evidence can be direct or indirect (physical or biological traces). A crime scene investigation team consists of police, detectives, crime scene investigators, medical investigators, and specialists. The investigation consists of recognizing, documenting, and collecting evidence.

20. Forensic Science: Fundamentals & Investigations, Chapter 2 20  Generally more reliable than testimonial (direct) evidence  Can be used to prove that a crime has been committed  Can corroborate or refute testimony  Can link a suspect with a victim or with a crime scene  Can establish the identity of persons associated with a crime  Can allow reconstruction of events of a crime The Value of Physical (Circumstantial) Evidence

21. Forensic Science: Fundamentals & Investigations, Chapter 2 21  Transient Evidence—temporary; easily changed or lost; usually observed by the first officer at the scene  Pattern Evidence—produced by direct contact between a person and an object or between two objects  Conditional Evidence—produced by a specific event or action; important in crime scene reconstruction and in determining the set of circumstances or sequence within a particular event  Transfer Evidence—produced by contact between person(s) or object(s), or between person(s) and person(s)  Associative Evidence—items that may associate a victim or suspect with a scene or each other; ie, personal belongings —Lee and Labriola in Famous Cases, 2001 Types of Physical (Circumstantial) Evidence

22. Forensic Science: Fundamentals & Investigations, Chapter 2 22 Examples of Transient Evidence  Odor—putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke  Temperature—surroundings, car hood, coffee, water in a bathtub, cadaver  Imprints and indentations—footprints, teeth marks in perishable foods, tire marks on certain surfaces  Markings

23. Forensic Science: Fundamentals & Investigations, Chapter 2 23 Examples of Pattern Evidence Pattern Evidence—most are in the form of imprints, indentations, striations, markings, fractures or deposits.  Clothing or article distribution  Gun powder residue  Material damage  Body position  Tool marks  Modus operandi  Blood spatter  Glass fracture  Fire burn pattern  Furniture position  Projectile trajectory  Tire marks or skid marks

24. Forensic Science: Fundamentals & Investigations, Chapter 2 24  Light—headlight, lighting conditions  Smoke—color, direction of travel, density, odor  Fire—color and direction of the flames, speed of spread, temperature and condition of fire  Location—of injuries or wounds, of bloodstains, of the victim’s vehicle, of weapons or cartridge cases, of broken glass  Vehicles—doors locked or unlocked, windows opened or closed, radio off or on (station), odometer mileage  Body—position, types of wounds; rigor, livor and algor mortis  Scene—condition of furniture, doors and windows, any disturbance or signs of a struggle Examples of Conditional Evidence

25. Forensic Science: Fundamentals & Investigations, Chapter 2 25 Classification of Circumstantial Evidence by nature:  Biological—blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacterial, fungal, botanical  Chemical—fibers, glass, soil, gunpowder, metal, mineral, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer  Physical—fingerprints, footprints, shoe prints, handwriting, firearms, tire marks, tool marks, typewriting  Miscellaneous—laundry marks, voice analysis, polygraph, photography, stress evaluation, psycholinguistic analysis, vehicle identification

26. Forensic Science: Fundamentals & Investigations, Chapter 2 26 Include some OR all of these seven major activities 1. Recognition—ability to distinguish important evidence from unrelated material  Pattern recognition  Physical property observation  Information analysis  Field testing 2. Preservation—collection and proper preservation of evidence Forensics Investigations

27. Forensic Science: Fundamentals & Investigations, Chapter 2 27 Forensics Investigations (cont’d) 3. Identification—use of scientific testing  Physical properties  Chemical properties  Morphological (structural) properties  Biological properties  Immunological properties 4. Comparison—class characteristics are measured against those of known standards or controls; if all measurements are equal, then the two samples may be considered to have come from the same source or origin.

28. Forensic Science: Fundamentals & Investigations, Chapter 2 28 5. Individualization—demonstrating that the sample is unique, even among members of the same class 6. Interpretation—gives meaning to all the information 7. Reconstruction—reconstructs the events of the case It involves: – forming a hypothesis of the sequence of events from before the crime was committed through its commission. – The evidence and witness statements need to fit the overall crime scenario – Evidence does not lie but it could be staged —Lee, Dr. Henry. Famous Crimes, 2001 Forensics Investigations

29. Forensic Science: Fundamentals & Investigations, Chapter 2 29 The Crime Scene “ 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, in The Boscombe Valley Mystery, 1892

30. Forensic Science: Fundamentals & Investigations, Chapter 2 30 Staged Crime Scenes When the lab results do not match up with the testimony of witnesses, it can mean the crime was staged; common examples include:  Staging a fire—to cover bankruptcy.  Staging a suicide—to cover a murder.  Staging a burglary—to collect insurance money.

31. Forensic Science: Fundamentals & Investigations, Chapter 2 31 Staged Crime Scenes To help determine whether a crime scene was staged, consider: Whether the type of wound found on the victim matches the weapon employed. Whether the wound could have been easily self-inflicted. The mood and actions of the victim before the event. The mood and actions of a suspect before the event.

32. Forensic Science: Fundamentals & Investigations, Chapter 2 32 Before a person can be convicted of a crime, You must prove …  that a crime occurred  that the person charged with the crime was responsible for the crime Top Reasons for Committing a Crime  Money  Revenge  Emotion—love, hate, anger Source of Evidence  Body  Primary and/or Secondary Crime Scene  Suspect(s) CORPUS Delicti “Body of Crime”

33. Forensic Science: Fundamentals & Investigations, Chapter 2 33 First Officer on the Scene A Assess the crime scene and assist those hurt D Detain the witness A Arrest the perpetrator P Protect the crime scene T Take notes

34. Forensic Science: Fundamentals & Investigations, Chapter 2 34 Crime Scene Survey Walk-through—may be performed by the first officer, the CSI, and/or sometimes the lead detective Purpose:  Note any transient or conditional evidence that could change over time.  Note weather conditions  Note points of entry or exit, as well as paths of travel within the crime scene  Record initial observations of who, what, where, when, and how  Identify special needs within the crime scene for personnel, precautions or equipment and notify superior officers or other agencies  After initital examination, mentally prepare a reconstruction theory

35. Forensic Science: Fundamentals & Investigations, Chapter 2 35 Documentation  Notes—date and time, description of the location, weather and environmental conditions, description of the crime, location of the evidence relative to other key points, the names of all people involved, modifications that have occurred and other relevant information  Photography—photos of scene and surroundings, mid-range to close-up photos with various angles of each piece of evidence, photos as viewed by any witnesses.  Sketches—inclusion of date, time, scale, reference points, distance measurements, names of investigators, victims, suspects, and a legend (key)  Videography—allows narration (non-subjective) to be included

36. Forensic Science: Fundamentals & Investigations, Chapter 2 36 Searching Methods  Line or strip method—best in large, outdoor scenes  Grid method—basically a double-line search; effective, but time- consuming  Zone method—most effective in houses or buildings; teams are assigned small zones for searching  Wheel or ray method—best on small, circular crime scenes  Spiral method—may move inward or outward; best used where there are no physical barriers

37. Forensic Science: Fundamentals & Investigations, Chapter 2 37 Crime Scene Sketch Date: August 14, 2005Criminalist: Ann Wilson Time: 11:35 amLocation: 4358 Rockledge Dr, St. Louis, Mo.

38. Forensic Science: Fundamentals & Investigations, Chapter 2 38 Collecting and Packaging  One individual should be designated as the evidence collector to ensure that the evidence is collected, packaged, marked, sealed, and preserved in a consistent manner  Each item must be placed in a separate container, sealed, and labeled  Most fragile is collected and packaged first  Different types of evidence require specific or special collection and packaging techniques  The body is the property of the coroner or medical examiner. The collection of evidence on the body is done by that department

39. Forensic Science: Fundamentals & Investigations, Chapter 2 39 Packaging Most items should be packaged in a primary container and then placed inside a secondary one. These are then placed inside other containers such as paper bags, plastic bags, canisters, packets and envelopes depending on the type and size of the evidence.

40. Forensic Science: Fundamentals & Investigations, Chapter 2 40 Chain of Custody There must be a written record of all people who have had possession of an item of evidence.  The evidence container must be marked for identification  The collector’s initials should be placed on the seal  If evidence is turned over to another person, the transfer must be recorded.

41. Forensic Science: Fundamentals & Investigations, Chapter 2 41 Investigators There must be a written record of all people who have had possession of an item of evidence.  The evidence container must be marked for identification  The collector’s initials should be placed on the seal  If evidence is turned over to another person, the transfer must be recorded.

42. Forensic Science: Fundamentals & Investigations, Chapter 2 42 Medical Examiner’s Responsibility  Identify the deceased  Establish the time and date of death  Determine a medical cause of death—the injury or disease that resulted in the person dying  Determine the mechanism of death—the physiological reason that the person died  Classify the manner of death  Natural  Accidental  Suicide  Homicide  Undetermined  Notify the next of kin

43. Forensic Science: Fundamentals & Investigations, Chapter 2 43 The Corspe “The way I see it, being dead is not terribly far off from being on a cruise ship. Most of your time is spent lying on your back. The brain has shut down. The flesh begins to soften. Nothing much new happens, and nothing is expected of you.” —Mary Roach. Stiff. W. W. Norton & Company. 2003

44. Forensic Science: Fundamentals & Investigations, Chapter 2 44................. Summary................. Summary First responding officers identify the extent of the crime scene, secure it, and segregate witnesses. Crime scene investigators document the crime scene. Evidence must be collected, packaged, and labeled. The evidence then is analyzed and interpreted to fit the crime scenario.

45. Forensic Science: Fundamentals & Investigations, Chapter 2 45 More Information For additional information on crime scene investigation, check out Court TV’s Crime Library: www.crimelibrary.com/criminal_mind/forensics/crimescene/5.html On Michael Baden and the autopsy: www.crimelibrary.com/criminal_mind/forensics/autopsy/1.html