Forensics Blood Splatter

Question 1

Who discovered platelets

Answer 1

William Osler

Question 2

Who created the first DNA profile

Answer 2

Alec Jeffreys

Question 3

Who discovered there were different blood types

Answer 3

Karl Landsteiner

Question 4

Who wrote the earliest reference to blood spatter analysis?

Answer 4

Dr. Eduard Piotrowski

Question 5

What are the scientific names for red blood cells, white blood cells, and platelets?

Answer 5

erythrocytes (red blood cells), leukocytes (white blood cells), and the thrombocytes (platelets)

Question 6

What is the function of red blood cells?

Answer 6

carry respiratory gases.
Oxygen and carbon dioxide, made in the bone marrow, no nucleus

Question 7

What is the function of white blood cells?

Answer 7

White blood cells fight disease and foreign elements.
Make in the lymph nodes, contain nucleus (DNA)

Question 8

What is the function of platelets?

Answer 8

Platelets aid in blood clotting and help repair damaged blood vessels.

Question 9

What percent of blood is composed of plasma?

Answer 9

55%

Question 10

What type of evidence is blood?

Answer 10

Class Evidence

Question 11

How is blood type specified?

Answer 11

by the presence or absence of certain antigens

Question 12

What percent of the population has each blood type? How many are Rh positive?

Answer 12

Type O (43%)
Type A (42%)
Type B (12%)
Type AB (3%)

Question 13

hat happens when incompatible blood types are mixed?

Answer 13

your body produces antibodies to destroy the donor’s blood cells

Question 14

What antigens and antibodies are associated with each blood type?

Answer 14

Type O: Anti A/B
Type B: Anti B
Type C: Anti A
Type AB: nil

Question 15

Who can each blood type donate to and receive from?

Answer 15

A Receive: A,O
A Donate: A, Ab
B Receive: B, O
B Donate: B, Ab
AB Receive: A, B, AB,O
AB Donate: AB
O Receive: O
O Donate: A, B, AB, O

Question 16

What did Balthazard do?

Answer 16

was the first researcher to analyze the meaning of the spatter pattern (1939)

Question 17

What case was blood spatter evidence used by the defense?

Answer 17

blood spatter evidence was used by the defense in the Sam Sheppard case

Question 18

What things can be determined from analyzing a blood spatter pattern?

Answer 18

help recreate a crime scene.
exclude suspects
How many people were there

Question 19

What are adhesion and cohesion, and how do they affect blood drops?

Answer 19

adhesive forces between a liquid and a surface are stronger, they will pull the liquid down, causing it to wet the surface. However, if the cohesive forces among the liquid itself are stronger, they will resist such adhesion and cause the liquid to retain a spherical shape and bead the surface

Question 20

What are satellites?

Answer 20

When blood falls from a height or at a high velocity, it can overcome its natural cohesiveness and form satellite droplets.

Question 21

What are spines?

Answer 21

When it falls onto a less-than-smooth surface, it can form spiking patterns around the drops called spines.

Question 22

What is meant by the directionality of blood?

Answer 22

The shape of an individual drop of blood provides clues to the direction from where the blood originated.

Question 23

Describe the characteristics of a blood drop that shows directionality.

Answer 23

A drop of blood that has a circular shape (equal width and length) indicates that the blood fell straight down. (as an example

Question 24

List and describe the 3 categories that blood stains can be classified in.

Answer 24

Passive – created due to gravity acting on the blood
olume, and flow)
Spatter – involve a force in addition to gravity, and show directionality and distribution of blood
Altered - stains that have been physically or physiologically changed

Question 25

What does the area of convergence tell you? What about point of origin?

Answer 25

The area of convergence is where the blood originated.

Question 26

How does height affect the size and shape of blood drops? What about angle of impact?

Answer 26

The higher the drop, the larger the area

the bloodstain pattern will become more elongated, elliptical, or oval in shape. The resulting bloodstain’s shape will indicate the direction of travel for that stain and thus, the origin of the drop of blood

Question 27

What is used to determine if the blood is human or animal?

Answer 27

Hexagon OBTI