1. Crime Scene Investigation and Evidence Collection
Identify the type of professionals who are present at a crime scene
Describe how evidence from a crime scene is analyzed
Summarize Locard’s exchange principle
Identify four examples of trace evidence
Distinguish between direct and circumstantial evidence
All Rights Reserved South-Western / Cengage Learning © 2012, 2009
Forensic Science: Fundamentals & Investigations, Chapter 2

2. Crime Scene Investigation and Evidence Collection
Summarize the three steps of a crime scene investigation
Explain the importance of securing the crime scene
Identify the methods by which a crime scene is documented
Demonstrate proper technique in collecting and packaging trace evidence

3. Wednesday 9/26 D day AIM: EVIDENCE DO NOW:
Designate each person at your table a role:
2 people – director
2 people – reporter
1 person – recorder
* Brainstorm different types of physical evidence used to help solve crimes

4. AIM: EVIDENCE
Read Lessons from the JONBENET RAMSET case - to be collected ( 1 per table )
Answer the following questions with your table:
1. What mistakes were made by the Boulder Police Department in securing the crime scene?
2. What specific kinds of evidence may have been compromised?
3. What could the police have done differently to secure the crime scene and the evidence?

5. Principle of Exchange
Established by Dr. Edmond Locard, the principle states:
When a person comes in contact with an object or another person, a cross-transfer of physical material can occur
Study of the material can determine the nature and duration of the transfer

6. Testimony by a witness about what that witness saw, heard, or did
Types of Evidence
Direct evidence
Testimony by a witness about what that witness saw, heard, or did

7. Types of Evidence Circumstantial evidence Physical evidence
also called Indirect
trace evidence
Physical evidence
e.g., fingerprints
Biological evidence
e.g., blood or hairs

8. Types of Evidence Explain why this would be or
would not be trace evidence

9. Wednesday 9/26 D day HOMEWORK
Read pg. 23
Write a paragraph explaining the difference between class and individual evidence. Make sure to give examples of each
Include the following questions in your discussion
Would class or individual evidence be considered direct or circumstantial
If evidence is circumstantial, would you classify class or individual evidence as physical or biological?

10. Thursday 9/27 E day AIM: EVIDENCE DO NOW: Have HW out on your table
Read article on Natalee Halloway What happened to Natalee Holloway in Aruba in 2005? This is an unsolved case in which questions have been raised about why crime scene investigators have not been able to find her body. In fact, investigators searched the island with an array of cutting-edge tools, from a remote-controlled submersible equipped with a video camera and sonar used for probing the water under bridges and in lagoons, to telescoping rods tipped with infrared sensors and cameras used for looking beneath manhole covers and into shadowy caverns.
Read the articles and make your own investigation by reading the primary
sources.
How would you decide?

11. Thursday 9/27 E day AIM: EVIDENCE DO NOW: Have HW out on your table
Answer the following questions individually:
Summarize Locard’s exchange principle
Identify four examples of trace evidence
Distinguish between direct and circumstantial evidence .

12. The Crime Scene Investigation Team
Who is at the crime scene?
Police
District attorney (possibly)
Crime scene investigators
Medical examiners
Detectives
Specialists

13. The Seven S’s of Crime Scene Investigation
Secure the scene (first responder police officer)
Separate the witnesses -Witnesses must not be allowed to talk to each other. Their accounts of the events will be compared
Scan the scene - The forensic examiners need to scan the scene to determine where photos should be taken. A determination may be made of a primary crime scene and secondary crime scene and priorities assigned regarding examination.

14. The Seven S’s of Crime Scene Investigation
4. Seeing the scene - Photos of the overall area and close-up photos with and without a measuring ruler should be taken.
5. Sketch the scene - An accurate rough sketch of the crime scene is made, noting the position of the body (if any) and any other evidence. (see crime scene sketch)
6. Search for evidence - Depending on the number
of investigators, a spiral, grid, linear, or quadrant pattern should be walked and location of evidence marked, photographed, and sketched (see crime scene search patterns
7. Secure the collected evidence - All evidence needs to be properly packaged, sealed, and labeled

15. Crime-Scene Sketch Form
A blank crime-scene sketch form showing the information that must be
provided with the sketch.

16. Crime-Scene Search Patterns
Four crime-scene search patterns.

17. Packaging the evidence
Crease a clean paper and place evidence in the X position
Fold in the left and right sides, and then fold in the top and bottom
Put the bindle into a plastic or paper evidence bag affixing a seal over the opening
Write your name on the seal

18. Evidence ID Forms

19. Chain of Custody
Maintaining a chain of custody log is essential to present credible evidence in court

20. Chain of Custody (cont’d.)
Bag the evidence Add identification Seal it Sign it across the sealed edge
Sign over to a lab technician Open bag on non-sealed edge
Return items to the evidence bag Seal evidence bag in another bag Sign the evidence log

21. Friday 9/28 F day AIM: EVIDENCE DO NOW:
Answer the following questions individually:
Identify the type of professionals who are present at a crime scene
Describe how evidence from a crime scene is analyzed
Explain the importance of securing the crime scene .

22. Analyze the Evidence
Facts result from collected evidence processed by the forensic lab
Lead detective aims to see how facts fit into the crime scenario

23. Analyze the Evidence Lab results can:
Show reliability of witness accounts
Establish the identity of suspects or victims
Show suspects to be innocent or link them with a scene or victim

24. Crime Scene Reconstruction
Crime scene reconstruction involves:
Forming a hypothesis of the sequence of events
From before the crime was committed through its commission

25. Staged Crime Scenes
When lab results don’t match up with the testimony of witnesses
Common examples:
Staging a fire—to cover bankruptcy
Staging a suicide—to cover a murder
Staging a burglary—to collect insurance money

26. Staged Crime Scenes Was the crime scene staged? Consider:
Does the type of wound match the weapon?
Could the wound be easily self-inflicted?
What were the mood and actions of the victim before the event?
What were the mood and actions of the suspect before the event?

27. Summary
Locard’s exchange principle:
Contact between people and objects can transfer material that can determine the nature and duration of the transfer
Evidence can be direct or indirect
Physical or biological traces
A crime scene investigation team consists of police, detectives, crime scene investigators, medical investigators, and specialists.

28. Summary
Investigations consist of recognizing, documenting, and collecting evidence.
First responding officers identify the extent of the crime scene, secure it, and segregate witnesses.
Crime scene investigators document the crime scene.
Evidence is collected, packaged, and labeled.
The evidence is analyzed and interpreted to fit the crime scenario.

29. Conclusion HW
Write an essay discussing the following questions – individually
If an eyewitness to a crime is a relative, friend, or acquaintance of the person committing the crime would he or she be a more or less reliable witness? Why or why not?

30. Wednesday 10/3 B day AIM: EVIDENCE DO NOW:
1. Have HW out on your desk (put into a pile by sink)
2. Re-read The Atlanta Child Murders Case
You are going to become the defense attorney for Wayne Williams.
What would your strategy be to create reasonable doubt and allow the jury to find Mr. Williams innocent?

31. Forensic Science: Fundamentals & Investigations, Chapter 2

32. Forensic Science: Fundamentals & Investigations, Chapter 2