1. Types of Evidence

2. 2 Objectives You will understand: The value of indirect and direct evidence in a court of law. That eyewitness accounts have limitations. What physical evidence can and cannot prove in court. That the forensic scientist’s main goal is to find a unique source for the evidence. You will be able to: Explain the difference between indirect and direct evidence. Describe what is meant by physical evidence and give examples. Distinguish individual evidence from class evidence. Determine the significance of class evidence.

3. Types of Evidence 3 What is an evidence?  Evidence is something that tends to establish or disprove a fact.  Evidence can include documents, testimony, and other objects.

4. Types of Evidence 4 Classification of Evidence Testimonial evidence is a statement made under oath; in court by a competent witness; also known as direct evidence or prima facie evidence. Physical evidence is any object or material that is relevant in a crime; also known as indirect/real evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, tool marks, impressions, glass.

5. Testimonial evidence includes oral or written statements given to police as well as testimony in court by people who witnessed an event. Eyewitness accounts can be a useful tool in helping investigators with analyzing a crime scene, but are not viewed to be highly reliable. In addition, eyewitness identifications (right or wrong) can have a big influence on the outcome of an investigation or trial. 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. Types of Evidence

6. 6  Age may play a role in the accuracy of an eyewitness’ statement or identification of a suspect. Children usually don’t remember as well as adults do. Older adults may have poorer eyesight or hearing than do middle-aged or younger adults, their eyewitness accounts may be less accurate.  The race of the witness may also play a role. The Cross Race Effect (CRE) is a phenomenon in which people are better at recognizing faces of their own race rather than those of other races.  The use of drugs can alter a person’s ability to recall the events of a crime even after they are no longer under the influence.  A person’s memory of an event can be influenced by other witnesses, investigators, and/or the media. Investigators use open-ended questioning and follow procedures for conducting line-ups to limit their influence on a witness’ memory of an event or identification of a suspect. What factors affect a person’s memory and their ability to identify a suspect? Witness Factors

7. Types of Evidence 7  A crime that is extremely traumatic for an eyewitness may affect his/her recall of the event. For example, a witness confronted with a weapon tends to focus on the weapon rather than the offender’s face.  Someone who is able to focus on a offender’s face for a minute or longer will tend to have a more accurate memory than someone who saw the person for only a few seconds.  Studies have shown that faces that are either highly attractive, highly unattractive, or distinctive are more likely to be accurately recognized. Simple disguises, such as hats or sunglasses, can interfere with accurate eyewitness identification. However, body piercings and tattoos increases the likelihood of an accurate identification.  The time of day in which the crime occurred as well as a person’s view of the scene may affect what a he/she is able to see. In addition, a person who is familiar with the area in which the crime took place, may have a better recall of the positions of the victims or suspects. Crime Scene & Suspect Factors

8. Types of Evidence 8  Now that your eyes and brain are warmed up, let’s test your observation skills a bit more.  You will have 2 minutes to study the photograph of a crime scene on the next slide.  Try to pay attention to details as you will be asked 10 questions about the crime scene!  You are not allowed to write anything down until after the time is up.  Ready? Crime Scene Challenge

9. Types of Evidence 9 Crime Scene Challenge

10. Types of Evidence 10 1. What color coffee mug was in the picture? Blue Red Yellow 2. When was the deadline? Yesterday Today Tomorrow 3. What time was on the clock on the wall? 10:40 11:05 1:55 4. How many sticky notes were on the whiteboard? Four Six Eight 5. Which of the following was NOT in the picture? Stapler Trash Can Printer 6. What was the name on the plaque on the desk? Bill Brian Carl 7. What color was the victim's shirt? Black Blue Red 8. How many plants were in the picture? None One Two 9. What was the color of the marker in the desk drawer? Red Blue Green 10. Where was the book in the picture? On a box In the trash can Under the body Source: http://forensics.rice.edu/html/picture_begin.html Crime Scene Challenge

11. Types of Evidence 11 Eyewitness Case Study  Ronald Cotton Case Watch Video What are the factors that may have influenced the accuracy of eyewitness? In you opinion, what could have been done to avoid this wrong conviction?

12. Types of Evidence 12 Eye Witness Case Study - Homework  Research the following Case: Serial Killer – Coral Eugene Watts Answer the following questions: Write case summary. What significant type of evidence was used to convict Coral Eugene Watts? Why did prosecutors want to reopen his case after so many years?

13. Types of Evidence 13 According to The Innocence Project (2008) "Eyewitness misidentification is the single greatest cause of wrongful convictions nationwide, playing a role in more than 75% of convictions overturned through DNA testing." Still, the criminal justice system profoundly relies on eyewitness identification and testimony for investigating and prosecuting crimes (Wells & Olson, 2003). Do You Know?

14. Types of Evidence 14 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. 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. FACES – A software program that offers many options to help you recreate a person’s facial features. Facial Composites

15. Types of Evidence 15 Value of Physical Evidence  Can prove that crime ahs been committed and set the scene for investigation  Can back up witness testimony or prove it false  Can link a suspect with a victim or crime scene  Can determine the identity of people associated with crime  Can allow investigators to reconstruct a crime

16. Types of Evidence 16 Physical evidence can be used to answer questions about: What took place at a crime scene The number of people involved The sequence of events Reconstruction A forensic scientist compares the questioned or unknown sample from the crime scene with a sample of known origin. e.g. The investigator finds paint of unknown origin on the bumper of a vehicle that is suspected to have been involved in a hit-and-run accident; it would be compared to the paint from the victim’s car (known origin).

17. Types of Evidence 17 Types of Physical Evidence Transient evidence is temporary; easily changed or lost; usually observed by the first officer at the scene. Pattern evidence is produced by direct contact between a person and an object or between two objects. Conditional evidence is 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.

18. Types of Evidence 18 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

19. Types of Evidence 19 Examples of Pattern Evidence Pattern evidence— mostly in the form of imprints, indentations, striations, markings, fractures, or deposits Glass fracture Tire marks or skid marks Fingerprints Bite Marks

20. Types of Evidence 20 Examples of Conditional Evidence Light—headlight, lighting conditions, lights on or off 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, odometer mileage Body—position and types of wounds; Scene—condition of furniture, doors and windows, any disturbance or signs of a struggle

21. Types of Evidence 21 Classification of Evidence by Nature Biological —blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacteria, fungi, botanical material Chemical —fibers, glass, soil, gunpowder, metals, minerals, narcotics, drugs, paper, ink, cosmetics, paint, plastic, lubricants, fertilizer Physical —fingerprints, footprints, shoeprints, handwriting, firearms, tire marks, toolmarks, typewriting Miscellaneous —laundry marks, voice analysis, polygraph, photography, stress evaluation, vehicle identification

22. Types of Evidence 22 Evidence Characteristics Individual —can be identified with a particular person or a single, specific, unique source Blood DNA Typing Fingerprints Class —common to a group of similar objects or persons

23. Types of Evidence 23 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.

24. Types of Evidence 24 Class vs. Individual Evidence  A torn T-shirt was found in the back seat of a suspect’s car. Two pieces of torn cloth were found at the scene of the crime. Can the two pieces be individualized to the T-shirt? Explain If the pieces of torn cloth match like a puzzle with the T-shirt, it would make the evidence from the crime scene “individual”.

25. Types of Evidence 25 Class vs. Individual Evidence  A cigarette butt was found at the scene of a crime. Is it individual evidence? Explain. No, because it could have come from any cigarette package.

26. Types of Evidence 26 Class vs. Individual Evidence  A broken test tube was found at a crime scene at a lab. Would small glass fragments be considered class evidence or individual evidence that can be uniquely associated with that? Explain. Individual evidence if the glass can match and class if it doesn’t.

27. Types of Evidence 27 Class vs. Individual Evidence  Some powder was found in a plastic bag in a suspect’s pocket. Some similar powder was found on the victim. Can the first powder be individualized to the second powder? Explain. If the two powders were determined to be chemically identical, does that prove they came from the same source? Explain. Even though the two samples are the same powder chemically, there is nothing unusual about them, and there is no way to prove that they came from the same source. It is, therefore, class evidence.

28. Types of Evidence 28 Class vs. Individual Evidence  A shoe print was found at the scene of a hit and run automobile accident. How can a suspect’s shoe be individualized to match a print? Explain. If they match, the print is individualized to the shoe. As we wear shoes we put a specific wear pattern on the shoe so even though hundreds of shoes were made, the wearer individuals the shoe.

29. Types of Evidence 29 Class vs. Individual Evidence  A bloody knife has been found in the backyard of a murder suspect. Under what circumstances could it be individualized? Or will it remain class evidence? Fingerprints on the handle would specifically identify the culprit. Blood analysis could tie it to the victim.

30. Types of Evidence 30 Forensic Investigations Include some or all of these seven major activities: 1.Recognition—the ability to distinguish important evidence from unrelated material Pattern recognition Physical property observation Information analysis Field testing 2.Preservation through the collection and proper packaging of evidence

31. Types of Evidence 31 3.Identification using scientific testing Physical properties Chemical properties Morphological (structural) properties Biological properties Immunological properties 4.Comparison of class characteristics 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 Forensic Investigations, continued

32. Types of Evidence 32 5.Individualization in demonstrating that the sample is unique, even among members of the same class 6.Interpretation—giving meaning to all the information Forensic Investigations, continued 7. Reconstruction of the events in the case Inductive and deductive logic Statistical data Pattern analysis Results of laboratory analysis —Henry C. Lee and Jerry Labriola, Famous Crimes Revisited, 2001

33. Types of Evidence 33 FBI Crime Lab  Watch FBI Crime Lab Documentary

34. Types of Evidence 34 Closure Activity  What are the different types of evidence?  What is the difference between testimonial evidence and physical evidence?  What are the factors that affect a person’s memory and his/her ability to identify a suspect?