Types of Evidence

1. Types of Evidence

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. 5 questions Lawyers should NEVER ask a witness in court: 1. Is it true that you were present until you left the building? 2. Who was it that got killed in the accident - you or your sister? 3. When the two cars collided, how far away from each other were they? 4. Was that the first time that your brother had committed suicide? 5. When he took your photo, were you present?

4. Learning Targets • Distinguish between testimonial and physical evidence. • What factors influence the reliability of eyewitness testimony? • What methods improve accuracy of an eyewitness identifying a suspect correctly?

5. Testimonial evidenceis a statement made under oath; also known as direct evidence or prima facie evidence. "at first face" or "at first appearance" Physical evidence is any object or material that is relevant in a crime; also known as indirect evidence. Examples are hair, fiber, fingerprints, documents, blood, soil, drugs, toolmarks, impressions, glass. Classification of Evidence

6. What kind of evidence is a fingerprint? Physical

7. What kind of evidence is a bitemark? Physical

8. What kind of evidence is DNA? Physical

9. What kind of evidence is this? Testimonial Video

10. What is testimonial evidence? 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.

11. Memory Challenge Directions: You will have 30 seconds to view the next screen. Try to memorize all 20 items you see! You are NOT allowed to write anything down You CANNOT talk to anyone else.

12. Items to remember ... Neuroscience for Kids - http://faculty.washington.edu/chudler/puzmatch1.html

13. You have 2 minutes to list as many of the items as you can! What do you remember? How did you do? All 20 – Awesome 15-19 – Great 10-14 – Pretty swell 5-9 – Could be better 4 or Less – Wake up

14. Selective Attention

15. Consider the Following • Observe the following image.

17. What color was the car to the left of the stop sign? What type of vehicle was sitting at the right of the stop sign? What color was the vehicle on the right? Which way was the stop sign facing?

18. Reliability of EyewitnessFalse Memory Experiments • Renowned psychologist Elizabeth Loftus conducted false memory experiments. In this experiment, subjects were shown an image of a car near an intersection. • The researchers asked the subjects who had seen the yield sign questions that deliberately included the words "stop sign." Researchers did the opposite with subjects who were shown the stop sign image. • Results of this experiment showed that subjects created false memories as they recalled not the image they had seen but rather the information that had been implanted. • http://www.ehow.com/info_7935459_forensic-psychology-experiments.html video

19. The Bunny Effect The Bunny EffectCBS News Video

21. False Memories (balloon ride) video

22. Video • Test

23. Jennifer Thompson’s • The Innocence Project-CBS 60 Minutes • 60 Minutes Part 2

24. Factors that affect accuracy: Nature of the offense and the situation in which the crime is observed Characteristics of the witness Manner in which the information is retrieved 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 Reliability of Eyewitness Innocence Project > 5:23

25. Did you know? 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). What factors affect a person’s memory and their ability to identify a suspect? Let’s do a little research! Source: http://www.helium.com/items/1276135-accurate-eyewitness-accounts

26. Age may play a role in the accuracy of an eyewitness’ statement or identification of a suspect. Studies have shown that when a lineup contains the actual culprit, both young children and elderly perform well, but when the lineup does not contain the culprit there is a higher rate of mistaken identifications. WitnessFactors Source: http://www.helium.com/items/1276135-accurate-eyewitness-accounts

27. Theraceof 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.

28. 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.

29. 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.

30. A crime that is extremely traumatic for an eyewitness may affect his/her recall of the event. Ex.: a witness confronted with a weapon tends to focus on the weapon rather than the perpetrator’s face. Crime Scene & Suspect Factors Source: http://www.helium.com/items/1276135-accurate-eyewitness-accounts

31. Someone who is able to focus on a perpetrator'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.

32. 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.

33. 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.

34. 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

36. Answer each question below. 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

37. FACES – A software program that offers many options to help you recreate a person’s facial features. 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. 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.

38. Eyewitness New technology is helping eyewitnesses to be able to describe suspects. A police composite may be developed from the witness testimony by a computer program or forensic artist. DEMO FACES—a composite program by InterQuest

39. You will need a calculator in a day or two! Make sure you have one. (Was on your supply list)

40. Physical Evidence • As a result of the influences on eyewitness memory, physical evidence becomes critical. • Identity and origin of physical evidence is main task of forensic scientist.

41. Forensic scientists consider the chemical and physical properties of materials they are investigating.

42. Physical Properties • Definition: anything you can observe or measurewithout changing the chemical identity of the substance • Length • Shape • Color • Temperature • Density • Hardness • Solubility [what it dissolves in] • Refractive index [how substance bends light]

43. Physical Changes • Changes in physical properties • Chemical composition doesn’t change • Tearing a piece of paper • Dissolving salt in water • Denting your car • Spilling milk

44. Chemical Properties • Can be observed when the substance changes its chemical composition Reactivity with : • Air (Flammability or oxidizing ability) • Water • Acid • Base Sample may be destroyed during testing VIDEO

45. Chemical Changes Changes in chemical composition; NEW substance MUST be present • Burning • Rusting • Formation of new gas • Formation of new solid • Change in pH • Growing new cells • Digestion

46. LET’S PRACTICE! • Make a T chart (with two headers) on your paper. Physical Changes|Chemical Changes • Sort the cards into the two categories. • Let me check. • Copy the examples into your chart. • Practice with the worksheet.

47. Work time! • Physical vs. Chemical Changes WS • Read/highlight back of WS, “Differentiating class and individual evidence” • Write a definition for class evidence and for individual evidence in your notebook as summary. • Work on witness experiment (plan, create surveys, find video clips or pics, talk to teachers, etc.)

48. Physical Evidence

49. If a forensic investigator has just the right evidence, what are some specific facts the evidence could prove? (For example, it can prove that a crime was committed.) List the following types of evidence in your journal. What do you think each one means? Share with your partner. Transient evidenceConditional evidence Circumstantial evidence Warm up (Think, Pair, Share!):

50. Is generally more reliable than testimonial evidence 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 reconstructionof events of a crime PhysicalEvidence