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Warm-Up Find 4 differences…
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Chapter 2: Types of Evidence
“You can learn a lot by just watching.” —Yogi Berra, former New York Yankees catcher and sage Kendall/Hunt
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Kendall/Hunt Publishing Company
Types of Evidence Two general types: Testimonial—a statement made under oath; also known as direct evidence or Prima Facie evidence Physical—any object or material that is relevant in a crime; also known as indirect evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, tool marks, impressions, glass. Kendall/Hunt Publishing Company
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Reliability of Eyewitness
Factors: Nature of the offense and the situation in which the crime is observed Characteristics of the witness Manner in which the information is retrieved Kendall/Hunt Publishing Company
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Reliability of Eyewitness
Additional factors: Witness’s prior relationship with the accused Length of time between the offense and the identification Any prior identification or failure to identify the defendant Any prior identification of a person other than the defendant by the eyewitness Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
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, physical evidence becomes critical. Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
Eyewitness Faces—a composite program by InterQuest Kendall/Hunt Publishing Company
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Value of Physical Evidence
Generally more reliable than testimonial Can 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 Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
Reconstruction Physical Evidence is used to answer questions about: what took place how the victim was killed number of people involved sequence of events A forensic scientist will compare the questioned or unknown sample with a sample of known origin. Kendall/Hunt Publishing Company
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Types of Physical Evidence
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 Kendall/Hunt Publishing Company
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Types of Physical Evidence
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 Kendall/Hunt Publishing Company
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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 Kendall/Hunt Publishing Company
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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 Kendall/Hunt Publishing Company
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Examples of Conditional Evidence
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 Kendall/Hunt Publishing Company
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Classification of 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 Kendall/Hunt Publishing Company
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Evidence Characteristics
Class—common to a group of objects or persons Individual—can be identified with a particular person or a single source Blood DNA Typing Fingerprints Kendall/Hunt Publishing Company
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Eyewitness Basics T. Trimpe
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Eyewitness Accounts Pros & Cons
Eyewitness accounts can be a useful tool in helping investigators with analyzing a crime scene, but are not viewed to be highly reliable. People are likely to view the same scene in different ways depending on their positions, line of sight, familiarity with the area, and other factors that can interfere with a person’s ability to remember details. Let’s test your “eyewitness” abilities! You will have 30 seconds to view the next screen. Try to memorize all 20 items you see!
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Items to remember ... Neuroscience for Kids -
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You have two minutes to list as many of the items as you can!
What do you remember? You have two minutes to list as many of the items as you can! How did you do? 20 - 5-9 - 4 or less – Wake up!
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Now You See It, Now You Don’t
Now that your eyes and brain are warmed up, let’s test your observations skills in the classroom. You will have one minute to take a look around. Try to pay attention to details! After the time is up, you will go to the hallway to take a quiz. No peeking allowed! Questions?
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How did you do? Red, yellow Butterflies Illinois College 14
5 (1 front, 4 side) Has element symbols on it 2 (or 3 with laptop) 2 3 11 butterflies 6 feet, 10 inches Blue or navy 10 feet Gray or light brown By the door 6 (5 Birds, 1 butterfly) South
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Facial Composites Investigators work with sketch artists and eyewitnesses to create facial composites, or sketches of a person’s face. Today many police departments are using facial reconstruction software to help them with this task. FACES Software – Offers many options to help you recreate a person’s facial features. The composite may be used internally to assist officers in identifying the suspect or used externally through local media (radio, TV, and newspaper) to solicit leads from citizens.
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Facial Composites You will have a chance to try to create a facial composite. You will need to pay close attention to the following features: The shape of the face The shape of the jaw The shape of the eyes The shape of the nose The width of the neck The shape & protrusion of the ears The presence of facial piercing The presence of facial hair, its color, & location The presence of facial markings, such as scars or tattoos Forehead or other facial lines The presence of eyeglasses or sunglasses The length, color, & texture of the person’s hair
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Class vs Individual Evidence
Which examples do you think could be individual evidence? Kendall/Hunt Publishing Company
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Forensic Investigations
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 Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
Investigations 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. Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
Investigations 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 Inductive and deductive logic Statistical data Pattern analysis Results of laboratory analysis —Lee, Dr. Henry. Famous Crimes, 2001 Kendall/Hunt Publishing Company
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Class vs Individual Evidence
These fibers are class evidence; there is no way to determine if they came from this garment. The large piece of glass fits exactly to the bottle; it is individual evidence. Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
People in the News Dr. Henry Lee—Chief Emeritus for Scientific Services and the former Commissioner of Public Safety for the state of Connecticut. He served as that state’s Chief Criminality from 1979 to Lee was the driving force in establishing the modern forensic lab in Connecticut. He has worked with many high profile cases including O.J. Simpson, Jon Benet Ramsey, and the “wood chipper” case. He is also seen on many of the true crime shows, including his own, “Trace Evidence: The Case Files of Dr. Henry Lee”. Learn more at his website: Kendall/Hunt Publishing Company
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Kendall/Hunt Publishing Company
FBI Investigation Read a case investigated by the FBI. Observe the various units of their lab and read the section: “How They Do That?”. Kendall/Hunt Publishing Company
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