spatter vs splatter splatter: random, unorganized spatter: not random, affect by gravity,...
TRANSCRIPT
![Page 1: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/1.jpg)
Section 1
Section 2
Section 3
Section 4
Chapter 9 Bloodstain Pattern
Analysis
Physiology of blood
Bloodstain Pattern Analysis
(Lab Journal)
Testing if it's Blood
Spatter vs Splatter
![Page 2: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/2.jpg)
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?
![Page 3: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/3.jpg)
The Sheppard Family Story
![Page 4: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/4.jpg)
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
![Page 5: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/5.jpg)
Sheppard Images
Crime Scene pictures
Spatter
![Page 6: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/6.jpg)
Crime Scene
pictures
![Page 7: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/7.jpg)
![Page 8: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/8.jpg)
Questions
1. What Biological evidence will blood provide,, in the bedroom?
2. What information does the Blood stain evidence provide?
![Page 9: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/9.jpg)
Dr Sam Sheppard July 4 1954, Reading:
http://www.youtube.com/watch?v=nV4zKeGM3fc HW link: main site:
http://law2.umkc.edu/faculty/projects/ftrials/sheppard/samsheppardtrial.html
http://law2.umkc.edu/faculty/projects/ftrials/sheppard/evidence.html
Police report: http://law2.umkc.edu/faculty/projects/ftrials/sheppard/sheppardreports.html
![Page 10: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/10.jpg)
Do Now: What Biological evidence Do Now: What Biological evidence will blood provide,, in the will blood provide,, in the bedroom?bedroom?
DNA Blood type(s) Tool marks/ voids Toxicological Reports Diseases Spatter marks (Blood trails,
movements)
![Page 11: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/11.jpg)
What can Spatter What can Spatter (Bloodstain Evidence)(Bloodstain Evidence) Evidence reveal:Evidence reveal:
1. .2. .3. .4. .5. .6. .7. .
![Page 12: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/12.jpg)
What can Spatter What can Spatter (Bloodstain Evidence)(Bloodstain Evidence) Evidence reveal:Evidence reveal:
1. Origin(s) of bloodstain2. Position of victim & assailant3. Movement of victim & assailant4. Number of blows/shots5. Distance of bloodstain from target6. Direction from which blood impacted7. Speed with which blood left its source
![Page 13: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/13.jpg)
Section 1Section
2Section
3
Section 4
c
d
b
a
a
c
fblood types
Rhesis Factor
Times
TimesTimes
b
Turns
Turns
used to detect
d
e
Chapter 9 Bloodstain Pattern
Analysis
Physiology of blood
Bloodstain Pattern Analysis
(Lab Journal)
Testing if it's Blood
Luminol
Kastle-Meyer Test
Leukomalachite green
E.L.I.S.A.
Human vs
Blood Proteins
Antibodies
Antigen-Antibody Response
Agglutination
Enzymes
Phosphoglucomutase Esterase D,
O43%, A 42%B 12%AB 3%
Rh+, 85%Rh-, 15%
MM 30%MN 48%NN 22%
Spatter vs Splatter
Probability Rule
4 Parts of the blood
Pink
Green
cleaned
![Page 14: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/14.jpg)
The study of antigen-antibody reactions.Tells us human vs. nonhumans
Serologists Questions1.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?
The study of antigen-antibody reactions.Tells us human vs. nonhumans
Serologists Questions1.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
![Page 15: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/15.jpg)
History of Blood!!!
With early Transfusions =instant death due to Coagulation1. 1901, Karl Landsteiner introduced the A-B-O system
2. 1937,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%
![Page 16: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/16.jpg)
![Page 17: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/17.jpg)
Structure of Blood:
1. Plasma, mostly water 2. Cells
Erythrocytes: (RBC) Leukocytes: (WBC) Platelets
![Page 18: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/18.jpg)
Major components of Blood,Plasma: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, Glucose3. Amino acids4. Fatty acids, 5. Vitamins, Hormones, 6. Cellular wastes
![Page 19: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/19.jpg)
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.
![Page 20: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/20.jpg)
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 length7. An absorbent blotter soaks up the imprint; it is
radioactively treated, and an X-ray photograph (called an autoradiograph) is produced
![Page 21: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/21.jpg)
Liquid BloodLiquid Blood Physical properties
viscosity surface tension specific gravity
Behaves as a projectile in motion biology, physics, maths
2
![Page 22: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/22.jpg)
Surface TensionSurface Tension
Resistance to penetration & separation Surface acts to reduce surface area
Smallest SA to Volume ratio is offered by sphere
3
![Page 23: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/23.jpg)
Dripping BloodDripping 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
![Page 24: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/24.jpg)
Drop size
.
Standard drop size 50ul (0.05ml)
.
Rapid bleeding gives slightly larger drop
Shaking/movementcasts off smaller drops
.
5
![Page 25: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/25.jpg)
Terminal Velocity v Distance Fallen(metric)
Terminal velocity as a function of distance fallen (metric)
0
1
2
3
4
5
6
7
8
0 1 2 3 4 5 6 7
Fall distance (m)
Ter
min
al v
elo
city
(m
/s)
6
![Page 26: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/26.jpg)
Terminal Velocity v Distance Fallen(imperial)
Terminal velocity as a function of distance fallen (imperial)
0
5
10
15
20
25
30
0 2 4 6 8 10 12 14 16 18 20
Distance fallen (f)
Te
rmin
al v
elo
cit
y (f
/s)
7
![Page 27: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/27.jpg)
Free Falling Blood Droplets
.
50 ul4.6 mm
7.5 m/s
4.2 to5.4 m
0.5 ul2.12 mm
2.4 to 3 m
.4.6 m/s
0.12 ul1.32 mm
0.84 to 1 m
.3.3 m/s
0.06 ul1.1 mm
0.5 to 0.65 m
.2.2 m/s
8
![Page 28: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/28.jpg)
Shape & Size of Shape & Size of BloodspotBloodspot
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
![Page 29: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/29.jpg)
Shape & Size of Shape & Size of BloodspotBloodspot
9
![Page 30: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/30.jpg)
Hat information does Hat information does this questionable this questionable drop pelt provide?drop pelt provide?
9
![Page 31: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/31.jpg)
Height FallenHeight 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, 1997
10
![Page 32: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/32.jpg)
Effect of Target Effect of Target SurfaceSurface
. .... .Spreads out smoothly ST of spreading edge is
broken by irregular surface
11
![Page 33: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/33.jpg)
Experiments with Falling Blood DropletsExperiments with Falling Blood Droplets
blood
dropper
ruler
Terazzo floor
whiteboard
rough paper towel
paper
Fabric (theatre green)
Height
Target Surface
12
![Page 34: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/34.jpg)
Height/Surface
Single drop of blood falling from various heights (m) onto various surfaces
smooth floor paper towel fabric
0.5
1
2
3
0.5
1
2
3
13
![Page 35: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/35.jpg)
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
![Page 36: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/36.jpg)
Angle of Angle of ImpactImpact
Adapted from Introduction to Forensic Sciences,W. Eckert, CRC, 1997
14
![Page 37: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/37.jpg)
Angle Angle of of ImpacImpactt
90
10
70
2030
60 50 40
Adapted from Introduction to Forensic Sciences,W. Eckert, CRC, 1997
80
Gravitational dense zoneat lower edge
14
![Page 38: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/38.jpg)
Wave Cast-offWave 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
![Page 39: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/39.jpg)
Point of ConvergencePoint of Convergence16
![Page 40: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/40.jpg)
Point of ConvergencePoint of Convergence16
![Page 41: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/41.jpg)
Point of ConvergencePoint of Convergence5 ml blood squirted from a syringe from height of 1 m
17
![Page 42: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/42.jpg)
Point of OriginPoint of Originlength
width
Angle of impact = arc sin W/L
Distance from point of convergence
Hei
ght a
bove
poi
nt o
f co
nver
genc
e
Origin
85 60 45 30
181
![Page 43: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/43.jpg)
Tracing Origin of Tracing Origin of BloodspotsBloodspots
Point of convergence method 2 dimensional image
Point of origin methodadds 3rd dimension to image
In practice:use of string & protractor at sceneuse of computer at laboratory
19
![Page 44: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/44.jpg)
Blood SpatterBlood Spatter
Low velocity (5 f/s, 1.5 m/s) e.g. free-falling drops, cast off from weapon
Medium velocity (25 - 100 f/s, 7.5 - 30 m/s) e.g. baseball bat blows
High velocity (>100 f/s, 30 m/s) e.g. gunshot, machinery
20
![Page 45: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/45.jpg)
Herbert Leon MacDonell,
Laboratory of Forensic Science,P.O. Box 1111,Corning,New York,14830,USA
21
![Page 46: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/46.jpg)
Low Velocity Blood Low Velocity Blood SpatterSpatter
Blood source subjected to LV impact < 5 f/s (1.5 m/s)
Spot diameter: mostly 4 - 8 mm some smaller, some larger
Free-falling drops (gravity only) Cast off from fist, shoe, weapon Dripping Splashing Arterial spurting
22
![Page 47: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/47.jpg)
Cast-off from WeaponCast-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
![Page 48: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/48.jpg)
Downswing of Downswing of HammerHammer
24
![Page 49: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/49.jpg)
Cast-off from WeaponCast-off from Weaponceiling
25
![Page 50: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/50.jpg)
Overhead swing with bloodied metal bar
26
![Page 51: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/51.jpg)
Cast-off Pattern (1/2)Cast-off Pattern (1/2)
27
![Page 52: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/52.jpg)
Cast off Pattern (2/2)Cast off Pattern (2/2)1
2
3
28
![Page 53: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/53.jpg)
What does this tell What does this tell you? you?
29
![Page 54: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/54.jpg)
Cast off Pattern (2/2) Cast off Pattern (2/2) ? Sequence? Sequence
29
![Page 55: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/55.jpg)
Cast off Pattern (2/2) Cast off Pattern (2/2) ? Sequence? 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
![Page 56: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/56.jpg)
Three overhead swings with hatchet
31
![Page 57: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/57.jpg)
Cast-off & medium velocity spatter32
![Page 58: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/58.jpg)
Cast-off & medium velocity spatter 233
![Page 59: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/59.jpg)
Cast-off PatternCast-off Pattern? Object? Object
34
![Page 60: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/60.jpg)
Cast-off PatternCast-off Patternfrom Handfrom Hand
35
![Page 61: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/61.jpg)
Cast-off pattern from bloodied hand swung in front of target
6” ruler
36
![Page 62: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/62.jpg)
.... ...
..
...
Drip PatternDrip Pattern Free-falling drops dripping into wet
blood Large irregular central stain Small round & oval satellite stains
.. .......
37
![Page 63: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/63.jpg)
Drip 1:Drip 1:
Blood dripping into itself from height of 1 m (8 drops)
38
![Page 64: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/64.jpg)
Drip 2Drip 2
Blood dripping into itself from height of 1 m (8 drops)
39
![Page 65: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/65.jpg)
Dripping onto steps
40
![Page 66: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/66.jpg)
Splash PatternSplash Pattern Volume > 1 ml
Subjected to LV impact Thrown Tipped
Large central irregular area surrounded by elongated peripheral spatter pattern
41
![Page 67: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/67.jpg)
Splash 1Splash 1
5 ml blood squirted from a syringe from a height of 1 m
42
![Page 68: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/68.jpg)
Splash 2Splash 2
5 ml blood squirted from a syringe from a height of 1 m
43
![Page 69: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/69.jpg)
Splash 3Splash 3
5 ml blood squirted from a syringe from a height of 1 m44
![Page 70: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/70.jpg)
Splash onto vertical surface
6” ruler
10 ml blood thrown 1 m onto a vertical target surface
45
![Page 71: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/71.jpg)
Stamping in blood 1
Area seen in close-up in next slide
46
![Page 72: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/72.jpg)
Stamping in blood Close-up of heel area
47
![Page 73: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/73.jpg)
Stamp 1Stamp 1
Blood pool (10 drops) before stamping
48
![Page 74: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/74.jpg)
Stamp 2Stamp 2
Blood pool (10 drops) after stamping49
![Page 75: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/75.jpg)
Arterial Spurt PatternArterial 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
![Page 76: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/76.jpg)
Small arterial spurt
spatter
broken pottery
51
![Page 77: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/77.jpg)
Neck incisions (scene)52
![Page 78: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/78.jpg)
Medium Velocity Medium Velocity Blood SpatterBlood Spatter
Blood source subjected to MV impact (25 - 100 f/s, 7.5 - 30 m/s)
Spot diameter: mostly 1 - 4 mm Blows with weapon (e.g. baseball bat)
54
![Page 79: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/79.jpg)
Medium velocity blood spatter.Point of impact 15 cm in front of vertical target surface
6” ruler
55
![Page 80: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/80.jpg)
Flick 1:Flick 1:
Blood flicked between middle finger & thumb onto a vertical smooth surface from a distance of 15 cm
56
![Page 81: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/81.jpg)
Flick 2:Flick 2:
Blood flicked between middle finger & thumb onto a vertical smooth surface from a distance of 15 cm
57
![Page 82: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/82.jpg)
High Velocity Blood High Velocity Blood SpatterSpatter
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
![Page 83: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/83.jpg)
Gunshot: back& forward spatter
Bloodstained foam held just above target surface.
Back-spatter on entry
Forward spatteron exit
bullet
Bullet passing L to R just above sheet
Bullet enters foam
bullet exits foam
59
![Page 84: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/84.jpg)
Gunshot Back SpatterGunshot 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
![Page 85: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/85.jpg)
Back spatter on steadying hand
61
![Page 86: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/86.jpg)
Gunshot Forward Gunshot Forward SpatterSpatter
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
![Page 87: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/87.jpg)
Forward spatter (5 ms after bullet impacted at 1000 f/s)
2.5 cm
blood soaked target
bullet
63
![Page 88: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/88.jpg)
6” ruler
Forward spatter onto target placed 15 cm behind point of
HV bullet impact (bullet passing towards screen) 1
64
![Page 89: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/89.jpg)
Forward spatter (closer view)65
![Page 90: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/90.jpg)
Forward spatter (closest view)
5 mm
66
![Page 91: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/91.jpg)
Wipe PatternsWipe Patterns Object moves through a wet
bloodstain Feathered edge suggests
direction
67
![Page 92: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/92.jpg)
Transfer PatternsTransfer 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
![Page 93: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/93.jpg)
Transfer from hair (hair-swipe) 1
69
![Page 94: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/94.jpg)
Transfer from hair (hair-swipe) 2
70
![Page 95: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/95.jpg)
Flow PatternsFlow Patterns Blood flows horizontally &
vertically Altered by contours, obstacles Often ends in pool
71
![Page 96: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/96.jpg)
Flow pattern
72
![Page 97: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/97.jpg)
Bloodspots on trousers78
![Page 98: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/98.jpg)
Serology
The analysis of the properties and effects of serums (blood, semen, saliva, sweat, or fecal matter) is called serology.
![Page 99: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/99.jpg)
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 animalWhy????
Animal makes antibodies because it is a foreign substance
![Page 100: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/100.jpg)
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!!!
![Page 101: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/101.jpg)
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
![Page 102: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/102.jpg)
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)
![Page 103: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/103.jpg)
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
![Page 104: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/104.jpg)
![Page 105: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/105.jpg)
It’s 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?
![Page 106: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/106.jpg)
Crime Scene analysis of blood
Confirming the stain is blood
(Presumptive tests)1. Luminol2. Kastle Meyer test3. Leukomalachite
green4. Hemastix ®
Confirming the blood is HUMAN
ELISA/Precipitin test
![Page 107: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/107.jpg)
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.
![Page 108: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/108.jpg)
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
![Page 109: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/109.jpg)
Characterization of blood stain
![Page 110: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/110.jpg)
1. Luminol Reaction
1. RBC contain hemoglobin2. 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)
![Page 111: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/111.jpg)
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.
![Page 112: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/112.jpg)
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.
![Page 113: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/113.jpg)
Characterization of blood stain
3. Hemastix ® is a dipstick for bloodMoisten with distilled water and dipped into the
samplePositive presence of blood detected if stick turns
green
![Page 114: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/114.jpg)
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
![Page 115: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/115.jpg)
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.
![Page 116: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/116.jpg)
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
![Page 117: Spatter vs splatter Splatter: random, unorganized Spatter: Not random, affect by gravity, predictable Blood stain Pattern: The pattern of a stain and](https://reader035.vdocuments.net/reader035/viewer/2022062618/551453cf550346494e8b5257/html5/thumbnails/117.jpg)
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???????