1. Bloodstain Pattern Interpretation Forensic Science

2. Bloodstain Pattern Interpretation

3. Equal to 8 % of total body weight - 5 to 6 liters of blood for males - 4 to 5 liters of blood for females - A blood loss of 1.5 liters is required to cause incapacitation. - A 40 percent blood volume (2 liters) loss is required to produce irreversible shock (death). Forensic Science Blood Facts – What Do You Know?

4. Droplet Characteristics? -Spherical during free fall. -Volume of drop: 0.05 ml. -Terminal velocity: 25.1 ft/sec. -High velocity droplets: <1 mm diameter. -High velocity droplets: 46 in. maximum distance. Forensic Science Blood FactsBlood Facts – What Do You Know?

5. 1514 – London – Richard Hunne -Jailed on 5 counts of heresy. -Found hanged in his jail cell. -Charged with “Self-murder”. -However blood evidence showed Hunne was bleeding BEFORE he was hung. Forensic Science Blood Facts - History

6. 1955 – Dr. Sam Sheppard? Dr. Paul Kirk testified that certain blood evidence on the wall had been “flung” from a bloody object that had been swung in an arc. Forensic Science Blood Facts - History

7. 1971 – Herbert MacDonell - Published Dept of Justice booklet titled: “Flight Characteristics and Stain Patterns of Human Blood” Forensic Science Blood Facts - History

8. What May Blood Evidence Be Able To Disclose? -Source of blood (origin). -Distance blood traveled. -Type of impact & direction. -Number of blows inflicted. -Position of victim during attack. -Position & movement of suspect. Forensic Science Blood Facts

9. What Is The “Target”? -The surface upon which blood has been deposited. Forensic Science Blood Facts

10. What Is “Spatter”? - Blood which has been dispersed as a result of force applied to a source of blood. ( Not “Splatter” ) Forensic Science Blood Facts

11. What Are “Spines”? - The pointed edges of a stain which radiate away from the central area to form the spatter. Forensic Science Blood Facts

12. What Is “Back Spatter”? - Blood directed back towards the source of energy or force that caused the spatter. Forensic Science Blood Facts

13. And “Forward Spatter”? - Blood which travels in the same direction as the force which caused the spatter. Forensic Science Blood Facts

14. And A “Parent Drop”? - A drop of blood from which a cast-off or satellite spatter originates. Forensic Science Blood Facts

15. Satellite Spatter? - Small droplets that break off from the parent spatter upon impact with a target surface. Forensic Science Blood Facts

16. Cast-Off Stain? – Blood that has been thrown from an object (ex: weapon) onto a target other than the impact site. Forensic Science Blood Facts

17. The Impact Site? – Usually the point on the body that received the blow / force and from which the blood was shed. Forensic Science Blood Facts

18. The “Flight Path”? - The path of the blood drop, as it moves through space, from the impact site to the target. Forensic Science Blood Facts

19. What Is A “Void”? - An absence of stains in an otherwise continuous bloodstain pattern. Forensic Science Blood Facts

20. What is this? Forensic Science Blood Facts Target Surface: = the floor ? Blood Stain 

21. Directionality Angle (answer) – The direction the blood was traveling when it impacted a target surface. The angle can usually be established from the geometric shape of a stain. Forensic Science Blood Facts

22. What is this? Forensic Science Blood Facts

23. Angle of Impact (answer) - The acute angle formed between the direction of a blood drop and the plane of the target surface. Forensic Science Blood Facts

24. Forensic Science Blood Facts

25. What is this? (red circle) Forensic Science Blood Facts

26. Point of Convergence - Common point in a 2 dimensional space to which the trajectories of several drops can be retraced. Forensic Science Blood Facts

27. What is this? Forensic Science Blood Facts

28. Point of Origin - Common point in a 3 dimensional space to which the trajectories of several drops can be retraced. Forensic Science Blood Facts

29. Direction of Flight? - The trajectory of a blood drop which can be established by its angle of impact and directionality angle. Forensic Science Blood Facts

30. A “Passive Drop”? - (Bleeding) Bloodstain drop(s) created or formed by the force of gravity acting alone. Forensic Science Blood Facts

31. Passive Drop Spatters Forensic Science Blood Facts

32. What Is “Misting”? - Blood which has been reduced to a fine spray, as a result of the energy or force applied to it. Forensic Science Blood Facts

33. Projected Blood? - Blood under pressure that strikes a target. ex: Expirated Blood Forensic Science Blood Facts

34. Expirated Blood? - Blood that is blown out of the nose, mouth or a wound as a result of air flow or air pressure, the propelling force. Forensic Science Blood Facts

35. What Is This? Forensic Science Blood Facts

36. A “Transfer Pattern” Forensic Science Blood Facts

37. What is this? Forensic Science Blood Facts

38. Forensic Science Blood Facts A “Wipe” (answer) – pattern created when a secondary target moves through an existing wet blood stain.

39. What is this? Forensic Science Blood Facts

40. Swipe (answer) – The transfer of blood onto a target surface by a bloody object that is usually moving laterally. Forensic Science Blood Facts

41. THE END Forensic Science Blood Facts