1. WARM UP 4/12 2. What can a gunshot wound show?
3. Give 3 things that can show a drowning.
4. What bone breaks during a hanging?
5. What is a contusion?
6. What is an incised wound?
7. What in the eyes can show signs of asphyxiation?
8. What are some signs of a close range shooting?

2. Ch 2 NOTES #5 BLOOD AS EVIDENCE 3/24

3. FORENSIC SEROLOGY
The study of blood and how it applies to the law

4. BLOOD FACTS
Main function is to carry oxygen and nutrients around the body
Average person has 6 liters of blood
Lose about 2.6 liters and life threatening
Made in bone marrow

5. BLOOD IS MADE OF:
1. PLASMA – yellowish fluid portion making up 55% of the blood
2. ERYTHROCYTES – (red blood cells)
- 1,000,000 per drop
- carries nutrient, O2, CO2, and wastes
- protein hemoglobin contains iron to help carry O2; gives color
3. LEUKOCYTES – (white blood cells)
- defends against bacteria, viruses, etc.
- produce antibodies or kill microbes themselves
4. PLATELETS – helps form blood clots
- hemophilia

6. RED BLOOD CELL

9. WHITE BLOOD CELL

11. PLATELET

14. BLOOD TYPING
In 1901, Karl Landsteiner discovered that there were 4 different blood types: A, B, AB, and O
He named it the A-B-O system
This helped understand why people were dying after transfusions or receiving blood

15. BLOOD TYPE IF CLUMPS WITH….
A Anti-A
B Anti-B
AB Anti-A and anti-B
O No clumping

16. BLOOD TYPE IS CLASS EVIDENCE – narrowed down to a group of people
FOUR BLOOD TYPES:
A (40% of population)
B (11%)
AB (4%)
O (45%)
****Presence or absence of A and B antigens on red blood cell surface determines blood type.

17. *A 5th blood protein was discovered – Rh factor
Rh + present
85% of Americans
Rh not present
15% of Americans

18. About 80% of the population are secretors
Secretors secrete their blood antigens into their tears, sweat, semen and saliva
The presence of any of these substances permits identification of the blood type of the suspect
Knowing the blood type allows you to rule out suspects rather than identify them. Why?

19. VIDEO CLIP

20. TESTS ON BLOOD Determine if it is blood a. KASTLE-MEYER COLOR TEST
*hemoglobin (protein in blood that carries oxygen) turns deep pink

21. b. HEMISTIX – strips, moisten, touch stain – turn green if blood
c. LUMINOL – spray, produces light if blood (even if diluted 10,000 X)
                      
Suspected bloodstain  on cloth?
Reveal by spraying with  luminol in the dark

23. Determine if it is human
a. PRECIPITIN TEST
* human anti-serum – antibody for human blood will react with blood and form white solid
* can be used on dried blood years old

24. BLOOD SPATTER
What you can tell…
DIRECTION IT
HIT
2. ANGLE HIT

26. HOW HARD IT
HIT
AREA AND # TIMES
IT HIT SURFACE

29. HEIGHT IT FELL FROM
6. EVENTS OF THE CRIME