1. Forensic Science: Fundamentals & Investigations, Chapter 2 1 What Makes a Good Observer? 1.Describe how I moved the first 3 objects in detail. 2.How many steps did I take to get from the desk to the back counter? 3.What color were my shoes 4.What was in my left hand as I walked from the back of the room to the front? 5.How was my hair when you first walked into the room? 6.What is missing from the back of the room? 7.What was the pattern of the eraser blocks on my desk at the start? 8.What was the pattern of the eraser blocks on my desk now (look up)? 9.What are the 4 ways to be a good observer?

2. Forensic Science: Fundamentals & Investigations, Chapter 2 2 Objectives: Chapter 2 Crime Scene Investigation and Evidence Collection Objectives: 1. Summarize Locard’s exchange principle 2. Identify four examples of trace evidence 3. Distinguish between direct and circumstantial evidence 4. Identify the methods by which a crime scene is documented

3. Forensic Science: Fundamentals & Investigations, Chapter 2 3 Principle of Exchange Established by Dr. Edmond Locard,  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

4. Forensic Science: Fundamentals & Investigations, Chapter 2 4 What could be Transferred? 1. Hair (eyelash) 2. Saliva 3. Skin 4. Blood 5. Fibers 6. Fluids 7. Nails 8. Tooth 9. Jewelry 10. Makeup 11. Scent 12. MANY MORE

5. Forensic Science: Fundamentals & Investigations, Chapter 2 5 Types of Evidence Direct evidence Testimony by a witness about what that witness saw, heard, or did

6. Forensic Science: Fundamentals & Investigations, Chapter 2 6 Types of Evidence Circumstantial evidence also called Indirect also called Indirect trace evidence trace evidence Physical evidence e.g., fingerprints e.g., fingerprints Biological evidence e.g., blood or hairs e.g., blood or hairs

7. Forensic Science: Fundamentals & Investigations, Chapter 2 7 Types of Evidence Explain why this would be or would not be trace evidence

8. Forensic Science: Fundamentals & Investigations, Chapter 2 8 The Crime Scene Investigation Team Who is at the crime scene? o Police and o District attorney (possibly) o Crime scene investigators o Medical examiners o Detectives o Specialists

9. Forensic Science: Fundamentals & Investigations, Chapter 2 9 The Seven S’s of Crime Scene Investigation 1. Secure the scene 2. Separate the witnesses 3. Scan the scene 4. Seeing the scene 5. Sketch the scene 6. Search for evidence 7. Secure the collected evidence

10. Forensic Science: Fundamentals & Investigations, Chapter 2 10 1. Securing the Scene police o First Responder- police Is it safe? Preserve any evidence (prevent transfer, loss or contamination)

11. Forensic Science: Fundamentals & Investigations, Chapter 2 11 2. Separating the Witnesses o DO NOT TALK TO EACHOTHER o Asked questions about the crime Who called it in Who did you see What did you see Can you identify persons Where were you

12. Forensic Science: Fundamentals & Investigations, Chapter 2 12 #3- Scanning the Scene o Where do you take pictures from? o Primary Vs Secondary Crime Scene Primary (Robbery at bank) Secondary (Suspect’s house)

13. Forensic Science: Fundamentals & Investigations, Chapter 2 13 4. Seeing the Scene o All photos taken (with and without rulers) o Triangulation of stationary objects included in photos Various angles and distances Close ups

14. Forensic Science: Fundamentals & Investigations, Chapter 2 14 5. Sketching the Scene o Note all positions, landmarks, doorways, windows, trees (outdoors) o Note all objects (placement is key)

15. Forensic Science: Fundamentals & Investigations, Chapter 2 15 6. Searching for Evidence o Walk the grid o Vacuums, Lights, Forceps

16. Forensic Science: Fundamentals & Investigations, Chapter 2 16 7. Securing and Collecting Evidence o Proper Packaging, sealing, labels Liquids/Arson  airtight & unbreakable container Biological  breathable so it can dry (prevent mold) o Paper Bindles o Chain of Custody Who did what and when

17. Forensic Science: Fundamentals & Investigations, Chapter 2 17 Closure o Tomorrow’s Crime Scene Clothing Observation

18. Forensic Science: Fundamentals & Investigations, Chapter 2 18 Packaging the evidence 1. Crease a clean paper and place evidence in the X position 2. Fold in the left and right sides, and then fold in the top and bottom 3. Put the bindle into a plastic or paper evidence bag affixing a seal over the opening 4. Write your name on the seal

19. Forensic Science: Fundamentals & Investigations, Chapter 2 19 Evidence ID Forms

20. Forensic Science: Fundamentals & Investigations, Chapter 2 20 Chain of Custody Maintaining a chain of custody log is essential to present credible evidence in court

21. Forensic Science: Fundamentals & Investigations, Chapter 2 21 Chain of Custody (cont’d.) 1. Bag the evidence Add identification Seal it Sign it across the sealed edge 2. Sign over to a lab technician Open bag on non-sealed edge 3. Return items to the evidence bag Seal evidence bag in another bag Sign the evidence log

22. Forensic Science: Fundamentals & Investigations, Chapter 2 22 Analyze the Evidence o Facts result from collected evidence processed by the forensic lab o Lead detective aims to see how facts fit into the crime scenario

23. Forensic Science: Fundamentals & Investigations, Chapter 2 23 Analyze the Evidence Lab results can: o Show reliability of witness accounts o Establish the identity of suspects or victims o Show suspects to be innocent or link them with a scene or victim

24. Forensic Science: Fundamentals & Investigations, Chapter 2 24 Crime Scene Reconstruction Crime scene reconstruction involves: o Forming a hypothesis of the sequence of events o From before the crime was committed through its commission

25. Forensic Science: Fundamentals & Investigations, Chapter 2 25 Staged Crime Scenes When lab results don’t match up with the testimony of witnesses Common examples: o Staging a fire—to cover bankruptcy o Staging a suicide—to cover a murder o Staging a burglary—to collect insurance money

26. Forensic Science: Fundamentals & Investigations, Chapter 2 26 Staged Crime Scenes Was the crime scene staged? Consider: o Does the type of wound match the weapon? o Could the wound be easily self-inflicted? o What were the mood and actions of the victim before the event? o What were the mood and actions of the suspect before the event?

27. Forensic Science: Fundamentals & Investigations, Chapter 2 27.............. Summary.................. Summary.... o Locard’s exchange principle: Contact between people and objects can transfer material that can determine the nature and duration of the transfer o Evidence can be direct or indirect Physical or biological traces o A crime scene investigation team consists of police, detectives, crime scene investigators, medical investigators, and specialists.

28. Forensic Science: Fundamentals & Investigations, Chapter 2 28................. Summary................. Summary o Investigations consist of recognizing, documenting, and collecting evidence. o First responding officers identify the extent of the crime scene, secure it, and segregate witnesses. o Crime scene investigators document the crime scene. o Evidence is collected, packaged, and labeled. o The evidence is analyzed and interpreted to fit the crime scenario.