Blood Types
This type of blood has B anitigens, A antibodies, and rh antibodies
B-
This type of blood has A antigens, B antibodies, and Rh antibodies
A-
This component of blood carries hemoglobin.
red blood cells
What can blood evidence help investigators determine? List three things.
locations of victim and attacker, whether or not victim or attacker was moving, where the attack took place, type of weapon used, location of other objects during the attack that may have been moved.
What is the first thing that investigators must do when they suspect that a stain is blood?
determine whether the stain is blood
This type of blood has A antigens, B antigens, and Rh antibodies
AB-
This type of blood has A antibodies, B antibodies, and Rh antigens
This component of blood produces fibrin that helps blood clot.
platelets
How does the shape of a blood drop change when the angle decreases from 90 degrees.
round at 90 degrees, gets longer as angle decreases and may have a tail at small angles
How does the size of a blood drop change as the height of the blood drop changes?
This type of blood has A antigens, B antibodies, and Rh antigens
A+
This type of blood has A antigens, B antigens, and Rh antigens
AB+
This component of blood is mostly water and carries dissolved proteins, nutrients, and wastes
plasma
Which direction does the tail of a blood drop point?
the direction that the blood is traveling
This type of blood spatter produces drops that are 4-6mm and are caused by an object moving at 5 m/s.
low velocity blood spatter
This type of blood has A antibodies, B antibodies, and Rh antibodies
O-
What happens when a type A antibody is added to a type A blood sample?
Agglutination - the A antibody binds to the A antigen on red blood cells, causing the cells to clump together.
This component of blood helps fight disease and foreign invaders to the body.
white blood cells
This type of blood spatter produces small drops (<1mm) and are caused by an objet moving at 100 ft/s.
high velocity blood spatter
This pattern happens when a bloody moving object brushes against a clean surface and transfers some blood to that surface.
swipe pattern
This type of blood has B antigens, A antibodies, and Rh antigens
B+
What test is done to determine whether a sample is human or animal?
preciptin test
Is blood class evidence or individual evidence? Why?
Class - many people have the same blood type. DNA sequencing needs to be done for blood to be individual evidence that is linked to one person.
This pattern is caused when a clean moving object brushes against a bloody surface, removing some of the blood from the surface.
wipe pattern
This type of blood spatter produces drops that are 1-4 mm and is caused by an object moving at 25 ft/s.
medium velocity blood spatter