As a result of these commercial observational activities, students will be able to note how many factors influence our ability to observe. Police collect eyewitness accounts of a crime understanding that this is not the most reliable source of information used in solving a crime.

1. When did the crime occur? 2. Who called in the crime? 3. Who is the victim?

1. Can the perpetrator be identified? 2. What did you see happen? 3. Where were you when you observed the crime scene?

Often, several different labs need to share a very small amount of evidence. It is important that the chain of custody be maintained. If the chain of custody is broken, then the evidence may not be allowed in a court proceeding. Identify the error in the following case. After obtaining the evidence, the first lab

Why were gloves necessary in the collection and handling of trace evidence? What other instruments could be used to improve on your ability to identify evidence? Demonstrate the correct techniques for collecting and handling evidence.

A home burglary has occurred. It appears the perpetrator entered after breaking a window. A metal safe had been opened by drilling through its tumblers. A suspect was seen running through the garden. Three suspects were interrogated and their clothing examined. List at least three examples of trace evidence that might be found on the

1. Some examples of trace evidence are listed. For each item, suggest a possible location where the trace might have originated. For example, broken glass fragments—headlight from a hit-and-run accident. 2. Explain the correct procedure for securing and examining a crime scene.

Describe how you can determine that the hair sample left at the crime scene is definitely a human hair and not an animal’s hair. Include calculations in your answer. Record your answer on the last page of the data sheet.

1. Is it possible that none of the hair samples matches the hair found at the crime scene? 2. Is it possible that more than one person’s hair matches the crime scene? 3. If someone’s hair does match the crime-scene evidence, does that mean that he or she committed the crime?

1. If someone’s hair did match the crime scene, what type of evidence could be obtained to indicate that the DNA at the crime scene is a match to their DNA and not to anyone else’s DNA? 2. Write a clear and organized essay. 3. Describe the basics of forensic hair analysis.