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Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and.

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Presentation on theme: "Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and."— Presentation transcript:



3 Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and the quantity of blood present can be important clues to the nature of the accident or crime. BSP Interpretation: what does the blod tell you?

4 The Sheppard Family Story

5 Dr Sam and Marilyn Sheppard Marilyn Sheppard 35 blows, 28 to the head Unknown instrument 12> inches None of these blows were fatal 2 broken teeth Torn fingernail. Blood found on most of the walls along with covering a dresser. Dr. Sam Sheppard: Bruises chipped teeth fractured vertebra in his neck. Found shirtless

6 Sheppard Images Crime Scene pictures Spatter

7 Crime Scene pictures


9 Questions 1. What Biological evidence will blood provide,, in the bedroom? 2. What information does the Blood stain evidence provide?

10 Dr Sam Sheppard July , Reading: HW link: main site: dtrial.html dtrial.html ml ml Police report: orts.html orts.html

11 Do Now: What Biological evidence will blood provide,, in the bedroom? DNA Blood type(s) Tool marks/ voids Toxicological Reports Diseases Spatter marks (Blood trails, movements)

12 What can Spatter (Bloodstain Evidence) Evidence reveal:

13 What can Spatter (Bloodstain Evidence) Evidence reveal: 1. Origin(s) of bloodstain 2. Position of victim & assailant 3. Movement of victim & assailant 4. Number of blows/shots 5. Distance of bloodstain from target 6. Direction from which blood impacted 7. Speed with which blood left its source


15 The study of antigen-antibody reactions. Tells us human vs. nonhumans Serologists Questions 1. Is the sample blood? 2. Is the sample animal blood? 3. If animal blood, from what species? 4. If human blood, what type? 5. Can the sex, age, and race of the source of blood be determined? Serology

16 History of Blood!!! With early Transfusions =instant death due to Coagulation , Karl Landsteiner introduced the A-B-O system ,Alexander Weiner, Rhesus monkey, Rh Factor was and over 100 factors actually must be considered when performing a transfusion. Most people are only familiar with the Rh factor, which is technically the D antigen. There are more than 256 antigens, and 23 blood group systems based on association with these antigens. Us Populations: O 43%, A 42%, B 12 %, AB 3%


18 Structure of Blood: 1. Plasma, mostly water 2. Cells Erythrocytes: (RBC) Leukocytes: (WBC) Platelets

19 Plasma: Major components of Blood, Plasma: Straw colored liquid consisting mainly (90%) of water and (7%) dissolved proteins. Can be found outside of the circulatory system. Also transports: 1. Proteins: (albumin, globulins, fibrinogen) 2. Salts, Glucose 3. Amino acids 4. Fatty acids, 5. Vitamins, Hormones, 6. Cellular wastes

20 DNA in BLOOD DNA can be extracted from blood (if white blood cells which always contain a nucleus are present), and also from sperm, bone marrow, tooth pulp, and hair roots.

21 Blood, however, is commonly used in DNA testing, as per the following steps: 1. Blood samples are collected from the victim, defendant, and crime scene 2. White blood cells are separated from red blood cells 3. DNA is extracted from the nuclei of white blood cells 4. A restrictive enzyme is used to cut fragments of the DNA strand 5. DNA fragments are put into a bed of gel with electrodes at either end 6. Electric current sorts DNA fragments by length 7. An absorbent blotter soaks up the imprint; it is radioactively treated, and an X-ray photograph (called an autoradiograph) is produced

22 Liquid Blood Physical properties viscosity surface tension specific gravity Behaves as a projectile in motion biology, physics, maths 2

23 Surface Tension Resistance to penetration & separation Surface acts to reduce surface area Smallest SA to Volume ratio is offered by sphere 3

24 Dripping Blood Blood drop grows until Wt (G) > S.T. Single drop breaks free (teardrop shape) Surface tension pulls in vertically Shape settles into sphere (0.05 ml) Does not break up until impact And horizontally Blood trickles downwards 4

25 Drop size. Standard drop size 50ul (0.05ml). Rapid bleeding gives slightly larger drop Shaking/movement casts off smaller drops. 5

26 Terminal Velocity v Distance Fallen (metric) 6

27 Terminal Velocity v Distance Fallen (imperial) 7

28 Free Falling Blood Droplets. 50 ul 4.6 mm 7.5 m/s 4.2 to 5.4 m 0.5 ul 2.12 mm 2.4 to 3 m. 4.6 m/s 0.12 ul 1.32 mm 0.84 to 1 m. 3.3 m/s 0.06 ul 1.1 mm 0.5 to 0.65 m. 2.2 m/s 8

29 Shape & Size of Bloodspot Depends mostly on nature of target surface texture (rough or smooth) porous or non porous Size is related to distance fallen, provided: standard 50 ul drop of blood There is little change in spot diameter beyond a fall distance of 1.2 m 9

30 Shape & Size of Bloodspot 9

31 Hat information does this questionable drop pelt provide? 9

32 Height Fallen Single drops of blood falling from fingertip onto smooth cardboard from various heights. No change in diameter beyond 7 ft. Adapted from Introduction to Forensic Sciences, W. Eckert, CRC,

33 Effect of Target Surface Spreads out smoothlyST of spreading edge is broken by irregular surface 11

34 Experiments with Falling Blood Droplets blood dropper ruler Terazzo floor whiteboard rough paper towel paper Fabric (theatre green) Height Target Surface 12

35 Height/Surface Single drop of blood falling from various heights (m) onto various surfaces smoothfloorpapertowelfabric

36 IMPACT ANGLE DETERMINATION ANGLE of IMPACT is the acute angle formed between the direction of the blood drop and the plane of the surface it strikes

37 Angle of Impact Adapted from Introduction to Forensic Sciences, W. Eckert, CRC,

38 Angle of Impact Adapted from Introduction to Forensic Sciences, W. Eckert, CRC, Gravitational dense zone at lower edge 14

39 Wave Cast-off. Parent drop wave cast-off Tail of wave cast-off points back to parent drop Tail of elongated stain points in direction of travel 15

40 Point of Convergence 16

41 Point of Convergence 16

42 Point of Convergence 5 ml blood squirted from a syringe from height of 1 m 17

43 Point of Origin length width Angle of impact = arc sin W/L Distance from point of convergence Height above point of convergence Origin

44 Tracing Origin of Bloodspots Point of convergence method 2 dimensional image Point of origin method adds 3rd dimension to image In practice: use of string & protractor at scene use of computer at laboratory 19

45 Blood Spatter Low velocity (5 f/s, 1.5 m/s) e.g. free-falling drops, cast off from weapon Medium velocity ( f/s, m/s) e.g. baseball bat blows High velocity (>100 f/s, 30 m/s) e.g. gunshot, machinery 20

46 Herbert Leon MacDonell, Laboratory of Forensic Science, P.O. Box 1111, Corning, New York, 14830, USA 21

47 Low Velocity Blood Spatter Blood source subjected to LV impact < 5 f/s (1.5 m/s) Spot diameter: mostly mm some smaller, some larger Free-falling drops (gravity only) Cast off from fist, shoe, weapon Dripping Splashing Arterial spurting 22

48 Cast-off from Weapon First blow causes bleeding Subsequent blows contaminate weapon with blood Blood is cast-off tangientially to arc of upswing or backswing Pattern & intensity depends on: type of weapon amount of blood adhering to weapon length of arc 23

49 Downswing of Hammer 24

50 Cast-off from Weapon ceiling 25

51 Overhead swing with bloodied metal bar 26

52 Cast-off Pattern (1/2) 27

53 Cast off Pattern (2/2)

54 What does this tell you? 29

55 Cast off Pattern (2/2) ? Sequence 29

56 Cast off Pattern (2/2) ? Sequence 1 (4 spots) 2 (3 spots) 3 (2 spots) If weapon does not pick up more blood, spatter from subsequent backswings becomes progressively less. In practice weapon picks up more blood with each successful blow. 30

57 Three overhead swings with hatchet 31

58 Cast-off & medium velocity spatter 32

59 Cast-off & medium velocity spatter 2 33

60 Cast-off Pattern ? Object 34

61 Cast-off Pattern from Hand 35

62 Cast-off pattern from bloodied hand swung in front of target 6 ruler 36

63 Drip Pattern Free-falling drops dripping into wet blood Large irregular central stain Small round & oval satellite stains

64 Drip 1: Blood dripping into itself from height of 1 m (8 drops) 38

65 Drip 2 Blood dripping into itself from height of 1 m (8 drops) 39

66 Dripping onto steps 40

67 Splash Pattern Volume > 1 ml Subjected to LV impact Thrown Tipped Large central irregular area surrounded by elongated peripheral spatter pattern 41

68 Splash 1 5 ml blood squirted from a syringe from a height of 1 m 42

69 Splash 2 5 ml blood squirted from a syringe from a height of 1 m 43

70 Splash 3 5 ml blood squirted from a syringe from a height of 1 m 44

71 Splash onto vertical surface 6 ruler 10 ml blood thrown 1 m onto a vertical target surface 45

72 Stamping in blood 1 Area seen in close-up in next slide 46

73 Stamping in blood Close-up of heel area 47

74 Stamp 1 Blood pool (10 drops) before stamping 48

75 Stamp 2 Blood pool (10 drops) after stamping 49

76 Arterial Spurt Pattern Blood exiting body under arterial pressure Large stains with downward flow on vertical surfaces wave-form of pulsatile flow may be apparent 50

77 Small arterial spurt spatter broken pottery 51

78 Neck incisions (scene) 52

79 Medium Velocity Blood Spatter Blood source subjected to MV impact ( f/s, m/s) Spot diameter: mostly mm Blows with weapon (e.g. baseball bat) 54

80 Medium velocity blood spatter. Point of impact 15 cm in front of vertical target surface 6 ruler 55

81 Flick 1: Blood flicked between middle finger & thumb onto a vertical smooth surface from a distance of 15 cm 56

82 Flick 2: Blood flicked between middle finger & thumb onto a vertical smooth surface from a distance of 15 cm 57

83 High Velocity Blood Spatter Blood source subjected to HV impact > 100 f/s, 30 m/s Fine mist: spot size < 0.1 mm Small mass limits spread to 1 m !Some larger droplets reach further Gunshot back-spatter from entry wound forward spatter from exit wound High speed machinery 58

84 Gunshot: back& forward spatter Bloodstained foam held just above target surface. Back-spatter on entry Forward spatter on exit bullet Bullet passing L to R just above sheet Bullet enters foam bullet exits foam 59

85 Gunshot Back Spatter Arises from entrance wound Passes back towards weapon & shooter Seen only at close range of fire Seen on: inside of barrel exterior of weapon hand, arm, chest of shooter 60

86 Back spatter on steadying hand 61

87 Gunshot Forward Spatter Arises from exit wound Passes forwards in same direction as shot More copious than back-spatter Can be seen at any range of fire Seen on nearby surfaces, objects, persons especially on wall behind victim 62

88 Forward spatter (5 ms after bullet impacted at 1000 f/s) 2.5 cm blood soaked target bullet 63

89 6 ruler Forward spatter onto target placed 15 cm behind point of HV bullet impact (bullet passing towards screen) 1 64

90 Forward spatter (closer view) 65

91 Forward spatter (closest view) 5 mm 66

92 Wipe Patterns Object moves through a wet bloodstain Feathered edge suggests direction 67

93 Transfer Patterns Wet, bloodied object contacts a secondary surface Transfer from: hand, fingers shoes, weapon hair Transfer to: walls, ceilings clothing, bedding Produces mirror-image of bloodied object 68

94 Transfer from hair (hair-swipe) 1 69

95 Transfer from hair (hair-swipe) 2 70

96 Flow Patterns Blood flows horizontally & vertically Altered by contours, obstacles Often ends in pool 71

97 Flow pattern 72

98 Bloodspots on trousers 78

99 Serology The analysis of the properties and effects of serums (blood, semen, saliva, sweat, or fecal matter) is called serology.

100 Immunoassay techniques Looking for Drugs, toxins, antibodies Antibodies not found in humans are synthesized Usually inject compound with drug (that you are testing for) into an animal Why???? Animal makes antibodies because it is a foreign substance

101 Immunoassay techniques Enzyme Multiplied Immunoassay Technique (EMIT): Detection of drugs through a antigen- antibody reaction. Radioimmunoassay (RIA) uses drugs that are labeled with radioactive drugs SO DETECTION occurs with any other related forms of that drug type!!!

102 Immunoassay techniques ~~EMIT screening Add subjects urine antibodies to detect material. For methadone: add methadone antibodies to the urine. [Conc] of antibodies not used indicates concentration used by the drug providing a related methadone concentration

103 Immunoassay techniques, ~~EMIT screening Marijuana's major active agent THC Tetrahydrocannabinol (3- 4.5%) Liquid Hashish oil 8-22 % THC Metabolized into THC-9-carboxlic acid Is detectable THC-9 in smokers urine is<1 mg (millionth of a gram) 2-5 days…10 days (sometimes)

104 Animal Responses: Polyclonal antibodies: antibodies produced by injecting animals with a specific antigen. A series of antibodies. A series of antibodies are produced responding to a variety of different sites on the antigen. Monoclonal Antibodies: collection of identical antibodies that interact with a single antigen n site. Mass produced by HYBIDOMA CELLS: spleen- cancer hybrids made in limitless supply


106 Its Red so it must be blood, right? When found at a CS, you must determine: If it is blood? Human vs animal. How closely it can be associated with a specific individual?

107 Crime Scene analysis of blood Confirming the stain is blood (Presumptive tests) 1. Luminol 2. Kastle Meyer test 3. Leukomalachite green 4. Hemastix ® Confirming the blood is HUMAN ELISA/Precipitin test

108 Presumptive tests: A simple test for a given substance using a reagent that changes color when mixed with the substance under investigation. Presumptive tests are not definitive and further confirmatory tests are always required. They are used extensively in forensic science. In general analytical chemistry, presumptive tests are often called spot tests. The first test is simply the use of a powerful light moved across every surface of a crime scene. That yields possible traces for visual inspection.

109 1. Luminol Luminol Reagent: Tests for by production of light rather than color. Extremely sensitive and can detect minute amounts of blood DOES NOT interfere with subsequent DNA analysis

110 Characterization of blood stain

111 1. Luminol Reaction 1. RBC contain hemoglobin 2. Mix luminol + Peroxide 3. The iron in homoglobin acts as a catalyst speeding up the reaction between Peroxide and luminol. 4. As reaction progresses, light is generated for about 30 seconds 5. (room should be dark)

112 1. Luminol sprayed across the scene because it reacts to blood by making it luminescent. It only takes about five seconds. The procedure requires that the room be considerably darkened in order to see the faint bluish glow, and the intensity of the glow increases proportionately to the amount of blood present. It works even with old blood or diluted stains, and can illuminate smear marks where blood has been wiped away. However, there is one problem with this test: luminol can destroy the properties of the blood that investigators need for further testing. Its use is limited to proving that blood is present even if not visible.

113 2. The Kastle-Meyer Color Test uses a solution of phenolphthalein and hydrogen peroxide on a piece of filter paper, and when blood of any quantity is present, it turns pink. However, it also turns pink in the presence of potatoes or horseradish, so care must be taken at the scene.

114 Characterization of blood stain 3. Hemastix ® is a dipstick for blood Moisten with distilled water and dipped into the sample Positive presence of blood detected if stick turns green

115 Characterization of blood stain 5. Precipitin Tests: (10-15 years) Serum for the precipitin test is obtained from rabbits which have produced antibodies to destroy a small quantity of human blood injected into them. A drop of this anti-human serum is added to suspect blood, which will precipitate its protein if it is of human origin. Electrophoretic method: ?? Western blotting test... analysis can detect one protein in a mixture of any number of... Western blotting tells you how much protein has accumulated in cells

116 Precipitin Tests: history Investigators use the precipitin test to determine whether the blood is of animal or human origin. German biologist Paul Uhlenhuth discovered that if he injected protein from a chicken egg into a rabbit, and then mixed serum from the rabbit with egg white, the egg proteins separated from the liquid to form a cloudy substance known as precipitin. In other words, it forms an antibody. In the forensic test for human blood: either a sample of the suspect blood is put into a test tube over the rabbit serum or it's used in the "gel diffusion" test, where it's placed in gel on a glass slide next to a sample of the reagent (anti-human serum). Passing an electric current through the glass, the protein molecules filter into the gelatin and toward each other. A line forms where they meet---called a precipitin line---that means the sample is human blood.

117 Precipitin Tests: history In 1925, another blood-related discovery important to criminal investigation was made. Around 80 percent of the human population were found to be "secretors," which means that the specific types of antigens, proteins, antibodies, and enzyme characteristic of their blood can be found in other bodily fluids and tissues. In the case of a secretor, investigators can tell the blood type by examining the saliva, teardrops, skin tissue, urine, or semen. In a rape case, for example, where the perpetrator is a secretor, potential suspects can be narrowed down through blood type analysis

118 Characterization of blood stain 5. ELISA/Precipitin Test: Human Antiserum determines if blood is from animal or human origin. HOW does it work? Remember ANTIGEN-Antibody Reaction???????

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