Blood Stain Evidence Flashcards
1
Q
Biology
A
- human adults have 4.5-6L
- predictable, forms a sphere almost immediately upon separating from source
2
Q
drying time
A
- dries perimeter into center, dried edges are resistant to water
3
Q
effect of height
A
- increases velocity until = gravity (terminal)
- increasing heights lead to increasing velocity until 7ft which is terminal
4
Q
2 basic categories
A
passive: result of an action other than direct force (drip)
dynamic: blood projected from sourced due to a force
5
Q
dripping blood
A
- trails show movement, pools show stationary
- pools and trails obey gravity, abnormalities imply disturbances
6
Q
Contact Stains
A
wipe: pre-existing stain disturbed by an object moving through it
swipe: bloody object moving against a non-bloody one
7
Q
Spatter
A
- dynamic
- blood mass broken into droplets radiating from a central source
- impact: gunshot, bunt force
- expiratory: exhalation
8
Q
Analyzing shape
A
- draw lines through long axis to find point of convergence
- 90 degrees = circular
- less than 90 degrees = elliptical
- stringing finds areas of origin
- hemospat is a digital stringing
9
Q
Cast-off stains
A
- bloodied object moved or swung
- straight or curved line of stains
