Course Flashcards
(32 cards)
Who is the researcher that experimented with rabbits?
Dr Eduard Piotrowski
Why is Dr Eduard Piotrowski important to BPA?
He recognized the dynamic nature of blood by conducting experiments using live rabbits and created graphic drawings of the results.
Who was the researcher who discovered the relationship between the width of an elliptical bloodstain and the length of an elliptical bloodstain?
Dr Victor Balthazard - there is a ratio and can information can be used in string method to determine area of origin
What is the first court case in Canada to hear bloodstain pattern evidence?
R v Sparrow in 1976
Why is R v Sparrow important to BPA
Bloodstain pattern analysis was conducted on clothing and a vehicle to convict a person of murder
How many types of blood were used in the study that compared Human blood to animal blood? What were they?
Four Bovine Equine Swine Sheep
What are the three categories of bloodstain patterns?
Gravity
Spatter
Transfer
What is a drip stain?
A blood stain resulting from a falling drop that formed due to gravity.
How many litres of blood does the average adult male have?
4 to 6 litres
What is Bloodstain Pattern Analysis?
It is the examination of the SIZE, SHAPE, LOCATION, and the distribution pattern of bloodstains, in order to provide an interpretation of the physical events which gave rise to their origin.
What are the two basic premises of BPA?
It is predictable and reproducible
How to do you seize clothing to be analyzed by a BPA later?
Place flat between two pieces of clean flat paper and then roll or fold.
Hang to dry
Photograph
What is the most important thing to do when seizing clothes from an accused?
Take photographs of the items on accused if possible and use scales.
What is the best type of stain to use use from clothing for a DNA analysis?
Spatter stains
What are some characteristics of fabric that cause limitation on the examination of clothing?
Type of fabric
Texture
Condition
Washed/unwashed
What are some limitations of BPA on clothing?
The appearance and directionality can be affected by a number of factors
Bloodstains can be distorted on certain fabrics
What is kinetic energy?
It is the energy that an object possesses due to its motion
What is forward spatter pattern?
It is a bloodstain resulting from the blood drops that traveled in the same direction as the impact force.
Example: the spatter away from a shooter
What is back spatter pattern?
A bloodstain pattern resulting from blood drops that traveled in the opposite direction of the external force applied; associated with an entrance wound created by a projectile.
Example: spatter back towards a shooter
What are the three Newtons Laws of motion?
An object at rest remains at rest and an object in motion, with a constant velocity, unless it experiences a net external force
Acceleration of an object is directly proportional to the force acting on it & is inversely proportional to mass
Every action has an equal and opposite reaction.
What are the two properties of blood?
Viscosity (thickness)
Surface tension (it is trying to stay together)
What is the area of convergence?
It is the 2 dimensional location of the blood source
What is the area of origin?
It is the 3 dimensional location of where the spatter originated.
What are e components of scientific methodology?
Identify the problem Gather information Document observations Formulate hypothesis and test if needed Analyze data Report data Review
