w1 blood Flashcards
shea are the elements of a crime
actus reus ( guilty act)
mens rea (guilty mind)
what is men’s rea
intention
recklessness
knowledge
how does the elements of a crime contribute to homocide
actus reus - destruction of life
mens rea - intention to kill
what is blood composed of?
red blood cells
white blood cells
plasma
what component of blood allows for presumptive test
the haemoglivin has peroxidase activity
colour presumptive tests
kastle meyer phenolphthalein
leucomalachite green
light producing presumptive tests
luminol
crime lites
what two factors are used to confirm whether a stain is blood
overall appearance ; colour and nature of stain
positive result on presumptive tests
what can give a false positive for presumptive tests
potato
what test can be used to distinguish between human blood
serological tests
if blood is located what do we need to address?
- type of bloodstain
- direction that blood travelled before landing
- distribution of blood stains
- identifiable patterns
- version of events
key parameters of blood dynamics
- viscosity
- surface tension
- velocity
- properties of impact surface
what conditions change bloods viscosity
increasing temperature decreases blood viscosity
increasing haematocrit increases viscosity
define viscosity relating to blood
measure of a fluids resistance to a change of shake or flow
define surface tension
measure of surface energy between two immiscible materials (blood and air)
