2. Bloodstain Pattern Analysis Collection and Preservation of Evidence Bloodstain Pattern Analysis 2

3. Goals Students- will understand the importance of blood spatter evidence at a crime scene Bloodstain Pattern Analysis 3

4. Objectives Students will: Discuss what can be learned from bloodstain patterns Explain the difference among low, medium, and high velocity spatters Determine the direction of blood spatter and points of convergence Bloodstain Pattern Analysis 4

5. 5

6. 6

7. A field of forensic study that deals with the physical properties of blood and patterns produced under different conditions as a result of various forces being applied to the blood Bloodstain Pattern Analysis 7

8. Pop Quiz Through Blood spatter analysis we can tell which of the following? A. B. C. D. Bloodstain Pattern Analysis 8

9. Enables reconstruction of events of the crime A tool that can help prove who committed the crime Bloodstain Pattern Analysis 9

10. Can determine: Point(s) of origin Type of force used Number of blows Sequence of events Position of victim and perpetrator Movement of people and objects Bloodstain Pattern Analysis 10

11. Bloodstain Pattern Analysis Determine direction blood was traveling Confirm/refute assumptions made by investigators of events and their sequence Confirm/refute statements made by witnesses of events and their sequence Bloodstain Pattern Analysis 11

12. Bloodstain Pattern Analysis Factors that do not affect analysis: Age of bleeding person Sex of bleeding person Disease present in bleeding person Alcohol level of bleeding person Temperature of scene Humidity of scene Bloodstain Pattern Analysis 12

13. Web Field Trip Did you all remember to bring in your permissions slips, signed by your mom? Here are the rules: Click onto the ips address on the next slide Magically, you will be transported to our web field trip site Watch/listen to the video (it is 6 minutes long). Then COME BACK! – no skipping out, sneaking off to the refrig, or checking out what is happening on TV! When you return, we will resume class. :o) Bloodstain Pattern Analysis 13

14. Please click onto the ips address below: http://www.youtube.com/watch?v=Od8YuwUT794 Bloodstain Pattern Analysis 14

15. Bloodstain Pattern Analysis When attempting to reconstruct the events that led to bloodstain spatter, document: Size of the stain Shape of the stain Distribution of stains in the pattern Location of stains Direction of the stains Density of the stain Bloodstain Pattern Analysis 15

16. Bloodstain Pattern Analysis Diameter of a drop of blood depends on: Volume of the blood Distance of the fall Surface texture Bloodstain Pattern Analysis 16

17. Bloodstain Pattern Analysis 17

18. Surface Texture 18Bloodstain Pattern Analysis

19. Direction of Travel Bloodstain Pattern Analysis 19 Stain shape will indicate direction of travel Round – 90 deg Elongated - angle Round smooth end – toward the origin Tail end points in the direction of travel

20. Proper Documentation Bloodstain Pattern Analysis 20

21. Points of Convergence Drawing lines along long axis of several stains will show a point of convergence at their origin Bloodstain Pattern Analysis 21

22. Area of Convergence Bloodstain Pattern Analysis 22

23. Impact Spatters Impact Spatter: Bloodstain pattern normally consisting of small spots of blood, varying greatly in size and number, which results from a source of blood being subjected to an impact Bloodstain Pattern Analysis 23

24. Impact Spatters Low Velocity Impact Spatter (LVIS) Medium Velocity Impact Spatter (MVIS) High Velocity Impact Spatter (HVIS) Bloodstain Pattern Analysis 24

25. Low Velocity Impact Spatter (LVIS) Bloodstain pattern caused by a low velocity impact being applied to a source of blood Sources: Open bleeding wounds Objects saturated with blood Bloodstain Pattern Analysis 25

26. Low Velocity Impact Spatter Bloodstain Pattern Analysis 26

27. Medium Velocity Impact Spatter (MVIS) Bloodstain pattern caused by moderate amount of force applied to a source of blood Sources Beatings Fist, boot, baseball bat Knifings Drops may travel long distances Bloodstain Pattern Analysis 27

28. Medium Velocity Impact Spatter Bloodstain Pattern Analysis 28

29. High Velocity Impact Spatter Bloodstain pattern caused by high amount of force applied to source of blood Sources Gunshots Explosion Mechanical accident (i.e. walking into airplane propeller) Does not travel very far Bloodstain Pattern Analysis 29

30. High Velocity Impact Spatter Bloodstain Pattern Analysis 30

31. Large Volume Bloodstain Patterns Splashed Patterns Relatively large amounts of blood Released under influence of gravity Travels as a mass of blood until it hits a surface Associated with traumatic bleeding from vessels under low pressure (veins) Bloodstain Pattern Analysis 31

32. Large Volume Bloodstain Patterns Projected Pattern – Gush Pattern Relatively large amount of blood Released under pressure Associated with traumatic bleeding from vessels under high pressure (artery) Bloodstain Pattern Analysis 32

33. Arterial Gush Bloodstain Pattern Analysis 33 Blood exiting the body due to traumatic bleeding (breached artery)

34. Large Volume Bloodstain Patterns Bloodstain Pattern Analysis 34 Projected Pattern

35. Large Volume Bloodstain Patterns Blood into Blood Created by drops of blood falling into pool of blood or creating pool of blood as it falls Consists of central pool of blood surrounded by satellite stains Satellite stains are usually circular and heavy in appearance Can easily be mistaken for impact splatter when viewed only on a vertical surface (side of a tennis shoe) Bloodstain Pattern Analysis 35

36. Blood into Blood Bloodstain Pattern Analysis 36 Results from blood dripping into blood

37. Cast-Off Patterns Created by blood thrown from a bloody object during “whip-like” termination of a back stroke Characterized by linear (in-line) stain pattern Shape of drops change from round on the end near origin to elongated at far end Can tell: Minimum number of blows Where the killer was when the blows were administered Bloodstain Pattern Analysis 37

38. Transfer/Contact Patterns Transfer of blood from one object to another as result of contact Recognizable imprint patterns can be created by contact with a bloody object Bloodstain Pattern Analysis 38

39. Transfer/Contact Pattern Created when a wet bloody surface comes into contact with a second surface 39Bloodstain Pattern Analysis

40. Transfer/Contact Patterns Swipe - stain created when a bloody object contacts a non-bloody surface in a swiping motion Wipe - stain created when a non-bloody object wipes through a bloody surface Bloodstain Pattern Analysis 40

41. Swipe Pattern Transfer of blood from a moving source onto an unstained source (i.e. bloody hair) Bloodstain Pattern Analysis 41

42. Wipe Pattern Created when a non-bloody object wipes through a bloody surface Bloodstain Pattern Analysis 42

43. Trail Pattern Results from drops of blood falling from a moving source of blood Composed of drops of blood forming a trail of blood Depending on speed of moving source of blood, the drops may show direction of travel Bloodstain Pattern Analysis 43

44. Trail Pattern Bloodstain Pattern Analysis 44

45. Voids and Limiting Angles Void – a pattern recognized by absence of blood in an area where blood would be expected, denoted by a distinct border Limiting Angle - can be used to limit location of the point of origin Consider which surfaces have bloodstains Point of origin of a bloodstain is limited to the area within range of that surface Bloodstain Pattern Analysis 45

46. Void Pattern Bloodstain Pattern Analysis 46 Recognized by the absence of blood in an area where blood would be expected, denoted by a distinct border

47. Bloodstain Pattern Analysis 47 QUESTIONS????