Chapter 10
Blood
Serology
*Serology is the ____________________________
*Including: __________________________________________________
*From 1950 to the late 1980’s, forensic serology was a most important part of lab
procedures.
*Now, more time, money, and significance is placed in ________________________
However, DNA testing is ___________________________________
*Most labs still use many of the basic serology testing procedures.
Blood Characteristics
*About _______ of your body is blood (cells suspended in liquid)
*Males: _______________
Females: ________________
-________ blood volume loss = _______________
-Loss of _______________ = ______________________
Blood Components
*_______________ (55% of the blood)
-Fluid part of blood
-Mostly ______________________
-The other 10% of plasma is __________________________________________
*___________ (45% of blood): 3 main types
1. ____________________ are red blood cells. They are responsible for
______________________________. Contain ______________________
2. ___________________are the white blood cells. They are responsible for
____________ the system of foreign invaders. Produce ___________________
3. __________________ or _______________ are responsible for blood clotting.
*_________________is the liquid that separates from the blood when a clot is formed
Historical Perspective of Blood Typing
*_________________________(1900)—discovered that there are __________________
of human blood based on the presence or absence of specific ________________
found on the surface of the red blood cells.
*_________________________ (1940)—discovered the ______________ by studying
the blood of the Rhesus monkey.
-________ of Caucasians, ________ of Black Americans and _______ of all Asians
are Rh positive
Blood Terminology
*______________________--based on having an A, B, both or no antigens on red blood
cells
*___________________--may be present on red blood cells; positive if present and
negative if not.
*__________________--a substance that can stimulate the body to make antibodies.
Certain antigens (________________) found in the plasma of the red blood cell’s
membrane account for blood type.
*_________________--a substance that reacts with an antigen
*______________________--clumping of red blood cells; will result if blood types with
different antigens are mixed.
Unknown Stain at a Scene
*Questions to be answered:
1. ______________________________
2. ______________________________
3. ______________________________
-Determine blood type, alcohol content, drugs present
-Determine the method(s) in which blood may have ___________________
Presumptive Tests for Blood Determination
1. ______________________________--a mixture of _____________________ and
___________________________; the hemoglobin will cause the formation of a
_______________________ if blood is present
2. _____________________________--reacts with the ____________ group in blood
causing a _______________________
3. ________________________--reaction with blood to produce ______________
(chemiluminesce)
Human vs. Animal Blood (How can you tell?)
*_________________________________
*_________________________--blood is injected into a rabbit; antibodies are
formed; the rabbit’s blood is extracted as an ___________________; the antiserum is
placed on sample blood. The sample will react with human proteins, if human blood is
present. This test is very sensitive and requires only a __________________________
*_________________________ has large, oval-shaped red blood cells with a nucleus
*______________________ red blood cells are small, round and lose their nucleus so
they can carry more oxygen.
Human Blood
*Red blood cells are most numerous; _____________________________
*White blood cells are larger and less numerous; __________________________
*Platelets are tiny, cellular fragments; _____________________________
Blood Typing
*Blood type _______ has _________________ on the surface of the cell and will
__________________________________________
*Blood type _______ has _________________ on the surface of the cell and will
__________________________________________
*Blood type _______ has ___________________________ on the surface of the
cells and will _________________________ with either type A or B blood
*Blood type _______ has ___________________________ and will agglutinate with
both A and B
**The charts below illustrate the details of Blood Typing for the purpose of Blood Transfusions
Recipients
Donors
O+




O+
A+
B+
AB+
OABAB-
A+
B+
AB+





Population Distribution of Blood types in the U.S.
Type
Percent
O
45
A
40
B
11
AB
4
0







A-
B-
AB-










Blood Pattern 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
Blood Spatter Evidence
*This field of forensic investigation deals with the ___________________________
and the patterns produced under different conditions as a result of various forces
being applied to the blood. Blood, as a fluid, ________________________________.
*___________________(1902-1970)—analyzed the blood stain pattern photos from the
Sam Sheppard case and was instrumental in _________________________ at his
second trial.
Blood Droplet Characteristics
*A blood droplet will remain _____________ in space ____________________________
*Once a blood droplet impacts a surface, a _________________________________
*A droplet falling from the same height, hitting the same surface at the same angle, will
produce a stain with the same basic shape.
*How will the shape change as the height is _______________________________?
Blood Droplet Volume
*A droplet contains approximately ______________________
*Is ________________________ for all blood droplets, but is general from
0.03cc to 0.15 cc
*Is directly dependent upon the surface of orifice from which it originates.
*The impact area is called the ___________________
Conditions Affecting Shape of Blood Droplet
*_______________________
*_______________________
*_________________ at which the blood droplet left its origin
*_________________
*_________________ of the _________________________
-On clean glass or plastic—droplet will have ___________________________
-On a rough surface—will produce ___________________________________
Questions Answered by Blood Spatter Interpretation
*The distance between the _______________________________________________
*The _______________________________ of the blood
*Movement and direction of a ________________________________
*The number of blows, shots, etc. causing the bloodshed and/or dispersal of blood.
*_________________________________________ that produced the bloodshed
*The __________________________ and/or object during bloodshed
*Movement of the victim _______________________________________________
Bloodstain Terminology
*_________________________--angle at which blood strikes a target surface
*_________________________--when a bloody object come into contact with a surface
and leaves a patterned blood image on the surface
*________________________--blood that is directed back toward the source of energy
*________________________--blood that is thrown from an object in motion
*________________________--bloodstains caused by contact between a wet blood
bearing surface and a second surface which may or may not have blood on it.
-________________--an image is recognizable and may be identifiable with a
particular object
-_______________--wet blood is transferred to a surface which did not have
blood on it
-_______________--a non-blood bearing object moves through a wet bloodstain,
altering the appearance of the original stain
*________________________--relates to the direction a drop of blood traveled in space
from its point of origin
*________________________--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 ________________________
-High velocity--greater than _____________________, usually
___________________: gives a ____________________________
-Medium velocity--_________________________
-Low velocity--_____________________________
Bloodstain Patterns
*The shape of a blood drop:
1. _________________--if it falls straight down at a _______________________
2. ________________--blood drops elongate as the angle decreases from 90 to
zero degrees; the angle can be determined by the following formula:
Impact
*The more ________________________________, the more ________________ the
stain
*__________________________are perfectly ____________ with _________________
taking on a more _________________________
*At about ___________________, the stain will begin to _________________________
*The more acute the angle, the easier it is to determine the _______________________
Bloodstain Patterns
*The _______________________________ the surface, the less the blood drop will
break apart
*The _______________________________ the surface, the more a blood drop will
break apart
*The ______________________ of the bloodstain _____________________________
____________________
Area of Intersection and Convergence
*The _______________________________________ can be determined by drawing
lines from the various blood droplets to the point where they __________________
*The ______________________________ is the point of origin; the spot where the
“blow” occurred. It may be established at the scene with measurement of angles by
use of ________________
Blood Evidence
*_______________________ for blood would include ___________________. If you
can determine the _________ you would have ______________________
*Bloodstain patterns are considered ____________________________ in a court room.
Experts could argue many points including direction of travel, height of the perpetrator,
position of the victim, left/right hand, whether the body was moved, etc.
Secretors
*______ of the population are _____________________. Their blood-type antigens are
found in high concentration in their body fluids such as saliva, semen, vaginal
secretions and gastric juice.
People in the News
*________________________ is considered as the father of modern bloodstain pattern
analysis.