Aim: How reliable is testimony made by eye witnesses? This lesson is part of a unit examining the probative value of different types of evidence.
Objectives: Students will be able to:
1) explain the difference between indirect and direct evidence;
2) discuss the limitations of eyewitness accounts
Motivation: Show students a series of optical illusions, such as the one depicted below. How reliable is our vision? Is seeing believing?
Content of the Lesson:
“Eyewitness accounts can provide important evidence leading to the arrest of a criminal. Juries are heavily influenced by eyewitness identification. How accurate are eyewitnesses? What might influence their accuracy?”
(Deslich & Funkhouser, 2006, p. 22) Important points to consider include:
1) The type of crime and how the witness saw it. Witnesses are more accurate at remembering some characteristics (sex, hair color) than others (height, age, specific race). Stress allows tend to narrow a victim’s focus and impair their ability to remember specific details.
2) Some types of witnesses are better at remembering than others. Children don’t usually remember as well as adults do. And older adults with poor eyesight or hearing may be less accurate than middle-aged or younger adults.
3) Interviewing techniques or how information is retrieved may also affect an eyewitness’s testimony.
4) Other factors include: whether or not the witness knew the accused, and how much time has transpired since the crime.
“The forensic scientist is most interested in physical evidence. Physical evidence can be any material or object. It can take almost any form: as large as a building, as fleeting as an odor, as small as a hair, or even submicroscopic, such as DNA evidence. The variety of physical evidence is virtually unlimited, as is the uniqueness of the crime. Physical evidence is generally much more reliable than testimonial evidence.” (Deslich & Funkhouser, 2006, p. 22)
Guided Practice for Application:
Activity #1: “How observant are you?” Adapted from an activity prepared by Shodor, http://www.shodor.org/workshops/forensic/lessons/observantlab.html
Testimony about personal experience is frequently used during an investigation. How accurately do people remember what they have seen? What factors may play a role in what we can remember and describe about something we have witnessed? Have students consider these questions as they complete the following activity.
1) Have students observe a picture for exactly 30 seconds. Tell them to look carefully at everything they think might be important.
2) After 30 seconds, have students answer the questions below in their notebooks:
a) What time was it on the clock
b) How many people were in the scene?
c) How many males? Females?
d) Describe the person at the front of the line. Was it a man or a woman? Was he or she wearing a hat? What kind of clothes was the person wearing? Could you tell how tall the person was? Did he or she have any distinguishing features?
e) What day of the month was it?
f) Did you notice anything unusual in the picture?
Compare students’ answers to the picture and discuss
Activity #2: “How observant are other people?”
Tell students, “In the last exercise you may have forgotten some details, and remembered other things incorrectly. As you experienced, your own memory can sometimes fool you, but what about other people’s memories? Try out this exercise to see how witnesses to the same scene remember different details. Think about how useful an individual’s testimony can be. Does it help to have several witnesses to a scene?”
1) Choose several people to be Observers. The rest of the class will play the role of Investigators.
2) Allow the Observers to look at a picture for 30 seconds. The Investigators should not look at the picture.
3) After 30 seconds, the Investigators should begin questioning the Observers.
Each Investigator should question each Observer. Then, the Investigators should attempt to reconstruct the scene based on the “eyewitness testimony”.
References: Deslich, B., & Funkhouser, J. (2006). Forensic Science for High School. Dubuque, IA: Kendall/Hunt.
How Observant Are Other People.doc 27k –
How Observant Are You.ppt 699k –How Observant Are You.ppt 699k –