Chapter 2: Types of Evidence “You can learn a lot by just watching.” —Yogi Berra, former New York Yankees catcher and sage

Chapter 2 Kendall/Hunt Publishing Company 1 Evidence  The difference between indirect and direct evidence  That eyewitness accounts have limitations  What is meant by physical evidence and give examples  What physical evidence can and cannot prove in court  The significance of individual and class evidence Students will learn:

Chapter 2 Testimonial vs. Physical Physical Evidence and Eyewitness Testimony Kendall/Hunt Publishing Company 2

Chapter 2 Kendall/Hunt Publishing Company 3 Eyewitness  A police composite may be developed from the witness testimony by a computer program or forensic artist.  “Perception is reality.”  As a result of the influences in eyewitness memory, ________ ______________ becomes critical. Faces—a composite program by InterQuest

Chapter 2 Kendall/Hunt Publishing Company 4 Reliability of Eyewitness Accounts Factors:  ________________and the situation in which the crime is observed  Characteristics of the __________  _________ in which the information is __________  ______________________with the accused/victim  ____________________between the offense and the identification  Any _________ identification or _________to identify the individual or iitem  Any prior identification of a person ____________________________ by the eyewitness

Chapter 2 Kendall/Hunt Publishing Company 5 Types of Evidence Two general types:  _____________—a statement made under oath; also known as direct evidence or Prima Facie evidence  ___________—any object or material that is relevant in a crime; also known as real evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, tool marks, impressions, glass.

Chapter 2 Kendall/Hunt Publishing Company 6 Value of Physical Evidence  Generally more ____________ than testimonial  Can prove that a crime has been committed  Can _____________or _________ testimony  Can _______ a suspect with a victim or with a crime scene  Can establish the _________ of persons associated with a crime  Can allow _______________ of events of a crime

Chapter 2 Kendall/Hunt Publishing Company 7 Reconstruction Physical Evidence is used to answer questions about:  _______ ______ _______ ______crime took place  _________ ____________  ____________ of events

Chapter 2 Kendall/Hunt Publishing Company 8 Types of Physical Evidence  __________—temporary; easily changed or lost; usually observed by the first officer at the scene  __________—often produced by direct contact between a person and an object or between two objects  ______________—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  ____________—often produced by contact between person(s) or object(s), or between person(s) and person(s)  _______________—items that may associate a victim or suspect with a scene or each other; ie, personal belongings

Chapter 2 Kendall/Hunt Publishing Company 9 Examples of Transient Evidence  _______—putrefaction, perfume, gasoline, urine, burning, explosives, cigarette or cigar smoke  ______________— surroundings, car hood, coffee, water in a bathtub, cadaver  __________ and indentations—footprints, teeth marks in perishable foods, tire marks on certain surfaces

Chapter 2 Kendall/Hunt Publishing Company 10 Examples of ________ ______ 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

Chapter 2 Kendall/Hunt Publishing Company 11 Examples of __________ ________  _______—headlight, lighting conditions  ________—color, direction of travel, density, odor  _____—color and direction of the flames, speed of spread, temperature and condition of fire  ___________—of injuries or wounds, of bloodstains, of the victim’s vehicle, of weapons or cartridge cases, of broken glass  ________—doors locked or unlocked, windows opened or closed, radio off or on (station), odometer mileage  ______—position, types of wounds; rigor, livor and algor mortis  ________—condition of furniture, doors and windows, any disturbance or signs of a struggle

Chapter 2 Kendall/Hunt Publishing Company 12 Classification of Evidence by _________  ___________—blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacterial, fungal, botanical  ___________—fibers, glass, soil, gunpowder, metal, mineral, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer  ____________—fingerprints, footprints, shoe prints, handwriting, firearms, tire marks, tool marks, typewriting  ____________—laundry marks, voice analysis, polygraph, photography, stress evaluation, psycholinguistic analysis, vehicle identification

Chapter 2 Kendall/Hunt Publishing Company 13 Evidence Characteristics  _______—common to a group of objects or persons  ______________—can be identified with a particular person or a single source Blood DNA TypingFingerprints

Chapter 2 Kendall/Hunt Publishing Company 14 Class vs Individual Evidence Which examples do you think could be individual evidence?

Chapter 2 Kendall/Hunt Publishing Company 15 Class vs Individual Evidence  The large piece of glass fits to the bottle—it is ___________ evidence  These fibers are ______evidence— there are millions like them.

Chapter 2 Kendall/Hunt Publishing Company 16 Statistical Significance  Probative value increases by considering class evidence  _____________ __________:  The combined probability of independent events is the product of the individual probabilities.

Chapter 2 Kendall/Hunt Publishing Company 17 Statistical Significance  When flipping a coin once, the probability of getting “tails” is ½ or.50 or 50%  When flipping a coin twice the probability of getting “tails” twice is ½ x ½ = ¼ or.5 x.5 =.25 or 25%

Chapter 2 Stats in Forensics  The decision makers must be given an idea of the significance of the scientific finding…is it common or rare?  The probability of independent events all occurring is the product of the probabilities of each of the events occurring.  Used in blood-grouping, DNA typing, etc. Kendall/Hunt Publishing Company 18

Chapter 2 Kendall/Hunt Publishing Company 19 Forensic Investigations Include some or all of these seven major activities 1. _____________—ability to distinguish important evidence from unrelated material  Pattern recognition  Physical property observation  Information analysis  Field testing 2. _____________—collection and proper preservation of evidence

Chapter 2 Kendall/Hunt Publishing Company 20 Investigations 3. ____________/characterization—use of scientific testing of properties  Physical  Chemical  Structural  Biological  Immunological 4. ______________—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.

Chapter 2 Kendall/Hunt Publishing Company 21 Investigations 5. _______________—demonstrating that the sample is unique, even among members of the same class 6____________—gives meaning to all the information 7. ___________—reconstructs the events of the case

Chapter 2 Kendall/Hunt Publishing Company 22 Known and Questioned Samples Scientists frequently compare _________________ or unknown samples (Q) Material collected from a known location but of unknown origin to ________________ or control samples (K) Material that comes from a known or proven source

Chapter 2 Kendall/Hunt Publishing Company 23 The Goal of Analysis  To identify the _________ of the evidence  To determine if there are _______ between victim, crime scene, and suspect  To __________________ the crime

Chapter 2 Kendall/Hunt Publishing Company 24 FBI Investigation Try a case that was set up by the FBI. Observe the various units of their lab and read the section: “How Did They Do That?”.