Forensic Science Quiz

List 3 components of blood

Platelets, red blood cells, plasma

What do blood cells have on their surface

Proteins

What do the letters (blood types) A, B, AB, & O stand for?

The type of antigens

What protein does a person have on their blood cells if they have (+) blood?

Rh Factor

What is impact spatter?

Force applied to liquid blood and the outcome of blood location

What is castoff?

The result of a bloody object in motion

Transfer staining

Blood is transferred from a bloodied surface to a non-bloodied surface

What must investigators do before analyzing blood stains?

Photograph the blood

What does area of convergence tell investigators?

Indicates the height of the incident that produced bloodshed

What does the area of origin tell investigators?

Where the victim was located at the time of the event

What two factors influence the amount of useful information that can be gathered from blood spatter?

Surface and force

What details can overlapping stains provide to investigators?

Force, timing, and instrument used

What tools are used to collect bloodstain evidence?

Cameras, cutting materials, evidence packing, sketching materials

What educational background is required of blood pattern analysis?

Math, physics, FBI’s scientific working group

What are the two phases of bloodstain pattern analysis?

Pattern analysis and reconstruction

Formula for angle of impact?

arcsin(W/L)

How does surface texture affect blood drop appearance?

Rougher surfaces produce messier stains, while smooth surfaces are clean and circular

How does height affect blood stain diameter?

As height increases, so does blood stain diameter

Features of type A blood (Antibodies, antigens, accept, give)

Anti-B antibodies, A antigens, can accept from A,O, can accept from AB, A

Features of type B blood (Antibodies, antigens, accept, give)

Anti-A antibodies, B antigens, can accept B,O, can give to AB, B

Features of type AB blood (Antibodies, antigens, accept, give)

None, A & B antigens, can accept all, can give to AB

Features of type O blood (Antibodies, antigens, accept, give)

Anti-A & Anti-B antibodies, none, can accept from O, can give to all

What are antigens?

Matches with blood type name

What are antibodies?

Opposite of blood type name