2. What is forensic science? Forensic Science is the application of science to the law. It often involves police officers and scientists from many branches of science working as a team to solve a crime.

3. How did Forensic Science catch their killer?

4. 1.Why do you think it is important that ‘Most forensic scientists are not police officers’? 2.The evidence in this case was collected from 4 major sites – can you name them? 3.How long did it take the Forensic Science Service to process all the evidence?

5. Investigating Blood Spatter Patterns

6. Categories of blood stains Blood patters can be roughly grouped into 3 categories: Passive Transfer Projected

7. Passive These are drops created only by the force of gravity. They can be further subdivided into Drops Drip patterns Pools Clots

8. Transfer These occur when a wet, bloody surface contacts another surface. This may lead to a recognisable footprint or hand/fingerprint.

9. Projected This is where the source of bleeding is subjected to another force – e.g. a blow or sudden movement. The size and shape of the drops produced depends on the size of the force.

10. What else can affect the patterns? The amount of blood The surface it lands on The height it drops from The direction it comes from Blood on glass – no distortion Blood on linoleum – distortion of edges Blood on wood – lots of distortion

11. Low velocity (1.5 m/s) –e.g. free-falling drops, cast off from weapon Medium velocity (7.5 - 30 m/s) –e.g. baseball bat blows High velocity (>30 m/s) –e.g. gunshot, machinery Types of Blood Spatter

12. Investigating blood patterns Your task is to carry out an investigation to see if the height that blood drips from (passive) affects how big the droplets are.

13. Blood patterns results Height (M)Size of drop (mm) Average size of drop (mm)

14. What is Forensic Science all about? Anthropology Ballistics Crime Entomology Evidence Fibres Trace Fingerprints Odontology Insects Serology Toxicology Pathology All about SCIENCEAll about SCIENCE!

15. Blood Spatter Analysis – extension higher ability CSI The origin is in the angle

16. History 1894 - Pitorowski wrote earliest reference to bloodstain pattern analysis 1939 - Balthazard was first to use physical interpretations of stains 1955 - Dr. Paul Kirk used bloodstain pattern interpretation as a defense witness in the Sam Shepherd case 1971 - Professor Herbert MacDonnell promoted bloodstain pattern interpretation as a tool for modern criminalistics 1983 – The International Association of Bloodstain Pattern Analysis was formed

17. Summary  What is Blood?  Determining Distance of Blood  Determining Direction of Blood  Types of Blood Stain Patterns

18. What is Blood?

19. Introduction to Blood

20. Blood Spatter (or splatter) Blood drops form different shapes and sizes Blood spatter analysis uses the shapes and sizes to reconstruct the crime scene.

21. Determining Distance Blood Falls Blood drops fall as small spheres Blood Spatter > Distance

22. Determining Distance Blood Falls  Drops form circle when hitting surface  Size depends on speed of blood drop Blood Spatter > Distance

23. Determining Distance Blood Falls Faster drop = larger diameter (size) Higher distance = larger diameter Due to air resistance, speed maxes out at distances above about 7 feet Blood Spatter > Distance

24. Determining Distance Blood Falls However, size of drop also depends on the volume of the drop. Volume depends on the object blood originated from (needle = small; bat = large). Blood Spatter > Distance

25. Determining Distance Blood Falls Since the volume of blood is unknown… The distance a drop has fallen cannot be measured. Blood Spatter > Distance

26. Effect of Surface  Smooth surface = smooth sphere  Rough surface may cause some splatter Blood Spatter

27. Determining Direction of Blood Narrow end of a blood drop will point in the direction of travel. Blood Spatter > Direction

28. Activity - 1 Obtain the blood solution, dropper, protractor and paper plate Drop one drop of blood from 3 feet above the plate with the plate at 90 degrees to the dropper (i.e. 0 degrees on the protractor) Drop 3 more drops in different locations but with each subsequent drop decrease the angle between the dropper and the plate and either take a picture or draw what you see Record the angles used and observe the drops Describe what you see

30. Angle (degrees) Picture (Drawn or photographed)Picture observations 90 (0 on protractor) Insert photo or drawingDescribe in detail what you see 60 (30 on a protractor) Insert photo or drawingDescribe in detail what you see 30 (60 on a protractor) Insert photo or drawingDescribe in detail what you see 10 (80 on a protractor) Insert photo or drawingDescribe in detail what you see

31. Conclusion Describe the relationship of angle of surface to blood pattern observed So angle angle of impact can be determined

32. Angle of Impact “The tail tells the tale” 90 degrees – 60 degrees – 30 degrees – 10 degrees –

33. Determining Direction of Blood If more than one drop (from spatter) results, the point of origin can be determined Blood Spatter > Direction

34. Determining Direction of Blood If more than one drop (from spatter) results, the point of origin can be determined Blood Spatter > Direction

35. Determining Direction of Blood This is a 2-dimensional point of origin. It is possible to determine the 3-D point of origin Blood Spatter > Direction

36. Determining Direction of Blood  The angle can be determined mathematically.  Width/Length, then take the inverse sin (sin -1 ).  This number is the impact angle (90 = perpendicular to surface; <10 at a sharp angle) Blood Spatter > Direction

37.  For each blood drop, a string can be guided back to the point of origin. Blood Spatter > Direction

39. Activity 2 3D blood splatter Determine the 3D angle of our blood spattered wall and the position of our victim

40. Types of Spatter  Spattered Blood = random distribution of bloodstains that vary in size  Amount of blood and amount of force affect the size of blood spatter.  Can result from gunshot, stabbing, beating Blood Spatter

41. Spattered Blood can:  Help determine the location of the origin of the blood source.  Help determine the mechanism which created the pattern. Blood Spatter

42. Spattered Blood In general, for higher impacts, the pattern is more spread out and the individual stains are smaller. Low impact = beating High impact = gunshot Blood Spatter

43. Types of Spatter Gunshot Spatter = can result in a mist-like spatter that indicates a gunshot.  Not all gunshots will result in misting.  If misting is present, it is most likely a gunshot. Blood Spatter

44. Gunshot Spatter Gunshots result in back spatter (where bullet enters) and forward spatter (where bullet exits). Blood Spatter

45. Types of Spatter Beating and Stabbing Spatter = larger individual stains First blow usually doesn’t result in spatter since there is not yet any exposed blood. Blood Spatter

46. Types of Spatter Satellite Spatter = free falling drops of blood that fall onto a spatter pattern.  These drips are usually much larger than impact spatter.  However, blood dripping into blood can create a spatter. Blood Spatter

47. Types of Spatter Castoff Pattern = Blood flung off of swinging object. Can reconstruct where assailant and victim were positioned. Blood Spatter

48. Types of Spatter Expirated Bloodstain Pattern = Blood can accumulate in lungs, sinuses, and airway. Forcibly exhaled.  Can appear like beating or gunshot pattern.  May be mixed with saliva or nasal secretions. Blood Spatter

49. Alteration of bloodstain over time  Blood dries and clots over time.  Difficult to estimate the time the blood exited the body.  Clotted smears can indicate time of movement. Blood Spatter

50. Blood analysis website Try to recreate some of these blood splatter patterns on A5 paper after reading through the website (without injuring any one please!!!!) You must consult your teacher when about to begin to ensure your safety Activity 3