Chapter 11 Study Guide
Created by: Meghan Meyer
BPA: Bloodstain Pattern Analysis
What can blood spatter tell an investigator?
- Type of velocity and weapon
- Number of blows
- Whether suspect was left or right handed
- Position of movements during and after attack
- Type of injuries
- How long ago crime was committed
- Whether death was immediate or delayed
How is blood detected at a crime scene?
- Light Source: High intensity lights or UV rays
- Blood Reagent Test: Presumptive tests used at scene to detect hemoglobin
- Luminol: Helps to find traces of blood if it has been cleaned or removed
- Fluorescence: Helpful in detecting latent or old blood
- LCV (Leuco Crystal Violet): Used to enhance the blood
Terms
- Spatter: Blood stains created from the application of force
- Origin/Source: Where the blood spatter came from
- Angle of impact: The angle at which blood strikes a surface
- Parent drop: Where the satellite drop originate from (big droplet)
- Satellite Spatters: Small drops of blood that come from parent droplet
- Spines: Pointed edge of stain that radiate from spatter
Blood Stain Patterns
Passive: Created because of gravity, series of drops or blood pools
Projected: Occur when force is applied to the source of blood (low, medium or high impact)
Transfer or Contact: When a wet/bloody object comes in contact with a target surface
What is blood?
Formed elements and plasma.
Erythrocytes (red blood cells)
Leukocytes (white blood cells)
O + - Considered universal donor because it can be given to anyone, regardless of blood type
A + -
B + -
AB + - Considered universal receiver because it can accept blood from anyone, regardless of blood type