2. FORENSIC SCIENCE INTRODUCTION Crime Scene Investigation

3. Complex Reasoning In Forensic Science Deductive (reasoning from the general to the particular) and Inductive Reasoning (reasoning from detailed facts to general principles) Classifying Comparing and Contrasting Problem Solving Analyzing Perspectives Constructing Support Error Analysis

4. 3 Locard’s Exchange Principle Whenever 2 objects come in contact with one another, they exchange some material (dust particles, hair, dead skin cells…) Locard strongly believed that every criminal can be connected to a crime by dust particles carried from the scene

5. 4 CORPUS DELICTI “Body of the Crime” You must prove : âthat a crime occurred âthat the person charged with the crime was responsible for the crime Top Reasons for Committing a Crime âMoney âRevenge âSex âEmotion--love, hate, anger Source of Evidence âBody âPrimary and/or Secondary Crime Scene âSuspect(s)

6. 5 INVESTIGATORS “The wise forensic investigator will always remember that he must bring all of his life experiences and logic to find the truth. This means common sense, informed intuition, and the courage to see things as they are. Then he must speak honestly about what it adds up to.” Dr. Henry Lee

7. 6 First Officer at the Scene ãAAssess the crime scene ãDDetain the witness ãAArrest the perpetrator ãPProtect the crime scene ãTTake notes

8. 7 Evidence Characteristics Class--common to a group of objects or persons Individual--can be identified with a particular person or source. ABO Blood TypingBlood DNA Typing

9. 8 Categories of evidence There are four major categories of evidence: Biological Chemical Physical Other

10. 9 Biological Evidence âBlood âSemen âSaliva âSweat/Tears âHair âBone âTissues âUrine âFeces âAnimal Material âInsects âBacterial/Fungal

11. 10 Chemical Evidence âFibers âGlass âSoil âGunpowder âMetal âMineral âNarcotics âDrugs âPaper âInk âCosmetics âPaint âPlastic âLubricants âFertilizer

12. 11 Physical (impression) âFingerprints âFootprints âShoe prints âHandwriting âFirearms âPrinting âNumber restoration âTyre marks âTool marks âTypewriting

13. 12 Others âLaundry marks âVoice analysis âPolygraph âPhotography âStress evaluation âPyscholinguistic analysis âVehicle identification

14. 13 Solving a problem Examining the crime scene worksheet In pairs… solve the problems related to the Millionaire’s Mansion burglary. You looked at suspects before… who did you think had an opportunity to commit the crime?

15. 14 Hand print on a window – male, female or child? Class Data Child (11-17) 65-180 Male (adult) 130-250cm 2 Female (adult) 88-180cm 2

16. 15 Printy Problem A bootprint was found on the frame of the French doors. The boot print had a surface area of 225 cm 2 Using data from the class – work out who could have committed the crime Personal Trainer (8), Chef (11), Chauffeur (6), Butler (10), Gardener (9)