1. FORENSIC SCIENCE Serology

2. Blood Characteristics
Plasma--fluid portion of the blood (55%)
Cells (45%)
Erythrocytes--red blood cells; responsible for oxygen distribution
Leukocytes--white blood cells; responsible for “cleaning” the system of foreign invaders
Thrombocytes--platelets; responsible for blood clotting
Serum--liquid that separates from the blood when a clot is formed

3. Blood Terminology
ABO blood groups--based on having an A, B, both or none of the factors on the red blood cell
Rh factor--may be present on the red blood cell; positive if present and negative if not
Antigen--a substance found on a red blood cell
Antibody--a substance that reacts with an antigen
Agglutination--clumping of red blood cells; will result if blood types with different antigens are mixed

4. Blood Genetic Terminology
Genotype--letters that represent the traits; ie, AA, AO, BO, BB, AB and OO
Phenotype--words that describe the traits
Heterozygous--different alleles for the same trait; ie: AO, BO, AB
Homozygous--the same alleles for the trait; ie: AA, BB, OO

5. Blood Questions to be answered: Is it blood? Is it human blood?
Whose is it?
Determine blood type, alcohol content, drugs present
Determine the method(s) in which blood may have been deposited

6. Presumptive Tests for Blood
Kastle-Meyer color test--phenolophthalein and hydrogen peroxide are mixed together the blood’s hemoglobin will cause the formation of a deep pink color
Leucomalachite test--leucomalachite green mixed with acetic acid and distilled water; then a drop of sodium perborate will turn blood green and then darken.
Luminol test--reaction with blood results in the production of light

7. Other Tests for Blood
Microcrystalline tests--add specific chemicals to the blood in order to form characteristic crystals
Takayama
Teichmann

8. Human vs Animal Microscopic survey
Precipitin test--blood is injected into a rabbit; antibodies are formed; rabbit’s blood is extracted as an antiserum; the antiserum is placed on sample blood. It will react with human proteins. This test is very sensitive and requires only a small amount of blood.
Characteristic Differences

9. Animal Blood
Frog Blood
Larger nucleic red blood cells

10. Human Blood
Numerous non-nucleic red blood cells--5 to 6 million per mm3
Larger but less numerous white blood cells 5 to 10,000 per mm3
Tiny, cellular fragments 350 to 500,00 per mm3 called platelets

11. Historical Perspective Of Blood Typing
Around 1900, Karl Landsteiner discovered that there are four different kinds of human blood based on the presence or absence of specific antigens found on the surface of the red blood cells.
In 1940 Landsteiner and Weiner reported the discovery of the Rh factor by studying the blood of the Rhesus monkey. 85% of Caucasians, 94% of Black Americans and 99% of all Asians are Rh positive.

12. Blood Typing A blood type has antigen A and will agglutinate with B.
B blood type has antigen B and will agglutinate with A.
AB blood type has antigen A and B and will not agglutinate with either A or B.
O blood type has neither antigen A or B and will agglutinate with either.

13. Blood Groups Can Give Blood To: Can Get Blood From Type Antigen
Antibody A A B
A, AB
O, A
B, AB
O , B B B A
Neither
A nor B AB
A and B AB
A, B, O, AB
Neither
A nor B O
A and B
A, B, O, AB O

14. Blood Reactions to Antiserum
Anti-A Serum
Anti-B Serum
BLOOD TYPE
Agglutination
No agglutination
No agglutination
Agglutination
Type A
Type B
Type AB
Type O

15. Population Distribution of Blood Types in the U. S.
Percent O 45 A 39 B 12 AB 4

16. Typing of Dried Blood Stains
Absorption-elution technique
Antiserum is placed on the blood stain. Antibodies combine with the specific antigens.
Unreacted serum is washed off the bloodstain.
Stained material is heated to 56 degrees C, breaking the antibody-antigen bond. This process is known as elution.
Known red blood cells are added. Agglutination will occur if antigens present on the added RBC’s were also originally on the stained material.

17. Differentiating Blood Types
Enzymes--proteins that speed up or slow down chemical reactions. Enzymes that exist in different forms are called polymorphic and can be broken down into their separate proteins called iso-enzymes.

18. Commonly Used Blood Enzymes and Proteins
Adenosine deaminase AD
Adenylate kinase AK
Carbonic anhydrase II CA II
Erythrocyte acid phosphatase EAP
Esterase D EsD
Glucose-6-Phosphate dehydrogenase G6PD
Glyoxylase U GLO I
Group-specific component Ge
Haptoglobin Hp
Peptidase A Pep A
Phosphoglucomutase PGM
6-Phosphogluconate dehydrogenase 6PGD
Transferrin Tf

19. PGM--phenotypes
Electrophoresis can separate the protein components into these 10 iso-enzymes. - +
Three of these are most common PGM 1+, PGM 2-1+ and PGM 2

20. EAP--phenotypes
Determined by the intensity of the fluorescence. The darker the band the more it fluoresced. B C A
A BA B CB C CA

21. BLOOD PATTERN/SEROLOGICAL RECONSTRUCTION
SCENE PATTERN RECONSTRUCTION
1. Stain condition
2. Pattern
3. Distribution
4. Location
5. Directionality
LAB RESULTS RECONSTRUCTION
1. Genetic marker typing
2. Age Determination
3. Source Determination
4. Race Determination
5. Sex Determination
From “Cracking Cases” by Dr. Henry C. Lee

22. Blood Stain Spatter
A field of forensic study which deals with the physical properties of blood and and the patterns produced under different conditions as a result of various forces being applied to the blood. Blood, as a fluid, follows the laws of physics. It is not influenced nor affected by race, gender, or age of the one bleeding.

23. BLOOD DROPLET Characteristics
A blood droplet will remain spherical in space until it drops onto a surface
Once a blood droplet impacts a surface, a bloodstain is formed.
A droplet falling from the same height, hitting the same surface at the same angle, will produce a stain with the same basic shape.

24. BLOOD DROPLET Volume Is approximately 0.05 cc
Is not the same for all blood droplets--from 0.03 cc to 0.15 cc
Is directly dependent upon the surface or orifice from which it originates
The impact area is called the target.

25. CONDITIONS EFFECTING BLOODSTAIN SHAPE
Size of the droplet
Angle of impact
Velocity at which the blood droplet left the original surface
Texture of the target surface
On clean glass or plastic--droplet will have smooth outside edges
On a rough surface--will produce scalloping on the edges

26. Questions Answered by Blood Spatter Interpretation
The distance between the target surface and the origin of blood at the time of blood shed
The point(s) of origin of the blood
Movement and direction of a person or an object
The number of blows, shots, etc. causing the bloodshed and/or the dispersal of blood.

27. Questions Answered by Blood Spatter Interpretation
Type and direction of impact that produced the bloodshed
The position of the victim and/or object during bloodshed
Movement of the victim and/or object after bloodshed

28. Bloodstain Terminology
Angle of impact--angle at which blood strikes a target surface.
Bloodstain transfer--When a bloody object comes into contact with a surface and leaves a patterned blood image on the surface.
Backspatter--blood that is directed back toward its source of energy.
Cast-off--blood that is thrown from an object in motion

29. Bloodstain Terminology
Contact stain--general term referring to bloodstains caused by contact between a wet, blood-bearing surface and a second surface which may or may not have blood on it
Transfer--image is recognizable and may be identifiable with a particular object
Swipe--wet blood is transferred to a surface which did not first have blood on it
Wipe--a non-blood bearing object moves through a wet bloodstain, altering the appearance of the original stain

30. Bloodstain Terminology
Directionality--relates to the direction a drop of blood traveled in space from its point of origin
Terminal velocity--the greatest speed to which a free falling drop of blood can accelerate in air. It is dependent upon the acceleration of gravity and the friction of the air against the blood--approximately 25:1 feet/second.
High velocity--greater than 100 feet per second; gives a fine mist appearance
Low velocity--5 feet per second or less
Medium velocity--5 to 25 feet per second.

31. Bloodstain Pattern
Terminal Velocity
Directionality
Angle of Impact

32. Blood Stain Patterns The shape of a blood stain:
Round--if it falls straight down at a 90 degree angle.
Elliptical--Blood droplet elongates as the angle decreases from 90 to 0 degrees. The angle can be determined by the following formula:
width = sine of the impact angle
length

33. IMPACT
The more acute the angle of impact, the more elongated the stain.
90 degree angles are perfectly round with 80 degree angles taking on a more elliptical shape.
At about 30 degrees the stain will begin to produce a tail.
The more acute the angle, the easier it is to determine the direction of travel.

34. Blood Stains
The harder and less porous the surface, the less the blood drop will break apart.
The softer and more porous the surface, the more a blood drop will break apart.
The pointed end of the blood stain faces the direction the stain is traveling.

35. Area of Intersection
The location of the blood source can be determined by drawing lines the various blood droplets to the point where they intersect. This is the blood’s origin.

36. Area of Convergence
The area of convergence is the point of origin; the spot where the “blow” occurred.
It is determined by drawing a line from the area of intersection straight up to where to where the angle of impact would intersect

37. CRIME SCENE
What evidence can you see in this crime scene? What story does the scene tell?

38. Bring In The Dogs!
The dog locates human scent. A closer look shows that the ashes have human remains and clothing. In addition, look closely at the rocks on the next slide.

40. Blood Evidence
Class evidence for blood would include blood type. If you can determine the DNA you would have individual evidence.
Blood stain patterns are considered circumstantial evidence in a court room. Experts could argue many points including direction of stains, height of the perpetrator, position of the victim, left/right hand, whether the body was moved, etc.

41. Sperm
Among the smallest and most highly specialized cells in the human body.
Has a head and a tail
Contains 23 chromosomes with the genetic material found in the head
Males release 2.5 to 6 milliliters of seminal fluid per ejaculation with approximately 100 million sperm per milliliter.
Magnified 400X

42. Semen Determination of Seminal Fluid Acid phosphatase color test
the presence of acid phosphatase, the enzyme secreted by the prostate gland into the seminal fluid, will turn purple when sodium alpha naphthylphosphate and Fast Blue B solution are placed on it.
It will also fluoresce under UV light when it comes in contact with 4-methyl umbelliferyl phosphate.

43. Semen (cont.) Determination of Seminal Fluid
Prostate Specific Antigen (PSA) or p30--unique to seminal plasma
P30 is isolated and injected into a rabbit where antibodies are produced (anti-p30)
The stain extract is place in one well of an electrophoresis plate and the anti-p30 in the opposite well. The electric is applied and the antigens and antibodies move toward each other. The formation of a precipitation line between the wells shows the presence of p30 in the sample stain. It must be seminal fluid.

44. Secretors
80% of people are considered secretors. Their blood-type antigens are found in high concentration in their body fluids such as saliva, semen, vaginal secretions and gastric juice. If you are a secretor, you will have a higher concentration of A and B antigens than does your blood!!
With the advent of DNA, the secretor evidence is not as important as it once was.