1. Crime Scene Photography “Blood Pattern Analysis” by Professor Mike Wiehe Professor Mike Wiehe

2. Goals Students - Will understand the importance of blood spatter evidence at a crime scene Students - Will understand the importance of blood spatter evidence at a crime scene

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

6. Bloodstain Pattern Analysis 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 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

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

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

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

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

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

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

14. Surface Texture

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

16. Proper Documentation

17. Points of Convergence Drawing lines along long axis of several stains will show a point of convergence at their origin Drawing lines along long axis of several stains will show a point of convergence at their origin

18. Area of Convergence

19. Force of the Blows Size of blood drops indicates force of blow Size of blood drops indicates force of blow Small force = Large drops Small force = Large drops Large force = Small drops Large force = Small drops Larger drops can travel farther than small drops because they have more momentum and air is less of an obstruction Larger drops can travel farther than small drops because they have more momentum and air is less of an obstruction

20. 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 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

21. Impact Spatters Low Velocity Impact Spatter (LVIS) Low Velocity Impact Spatter (LVIS) Medium Velocity Impact Spatter (MVIS) Medium Velocity Impact Spatter (MVIS) High Velocity Impact Spatter (HVIS) High Velocity Impact Spatter (HVIS)

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

23. Low Velocity Impact Spatter

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

25. Medium Velocity Impact Spatter

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

27. High Velocity Impact Spatter

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

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

30. Arterial Gush Blood exiting the body due to traumatic bleeding (breached artery) Blood exiting the body due to traumatic bleeding (breached artery)

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

32. Blood into Blood Results from blood dripping into blood Results from blood dripping into blood

33. Cast-Off Patterns Created by blood thrown from a bloody object during “whip-like” termination of a back stroke Created by blood thrown from a bloody object during “whip-like” termination of a back stroke Characterized by linear (in-line) stain pattern Characterized by linear (in-line) stain pattern Shape of drops change from round on the end near origin to elongated at far end Shape of drops change from round on the end near origin to elongated at far end Can tell: Can tell: Minimum number of blows Minimum number of blows Where the killer was when the blows were administered Where the killer was when the blows were administered Bloodstain Pattern Analysis 33

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

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

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

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

38. Wipe Pattern Created when a non-bloody object wipes through a bloody surface Created when a non-bloody object wipes through a bloody surface

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

40. Trail Pattern

41. 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 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 Limiting Angle - can be used to limit location of the point of origin Consider which surfaces have bloodstains Consider which surfaces have bloodstains Point of origin of a bloodstain is limited to the area within range of that surface Point of origin of a bloodstain is limited to the area within range of that surface

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

43. QUESTIONS????