Blood Evidence & Spatter Test Review

Red blood cells

The type of blood cell that carries the proteins used to determine a person's blood type.

Protein

A protein and B protein, and Rh proteins are used to determine human blood type.

O-

The blood type of a person who has none of the blood type proteins (A, B, or Rh).

Blood type evidence

Classified as class evidence because it is not unique to an individual.

Anti-A serum

If the blood does not clump when this is added, it means the blood does not have the A protein.

Presumptive Test

A test to determine if a stain is actually blood or another substance.

Luminol

A chemical used to locate the position of possible blood that was cleaned up and is not visible to the eye.

High velocity blood pattern

A bloodstain pattern characterized by very small droplets resembling a mist, typically associated with a gunshot.

Cast-off pattern

A bloodstain pattern created when blood is flung from an object. Can be used to determine approximate object size, location of a victim or the number of blows received.

Transfer pattern

A bloodstain pattern created when an object with blood on it, such as a shoe, leaves a print on a surface.

Wipe pattern

A blood stain pattern created when an object moves through an existing bloodstain.

Satellite drops

Small droplets that break away from a main blood drop, often created when blood drips from high above into existing blood on the floor.

Spines

The pointed or elongated edges of a blood drop, which are often expected to be more numerous when blood falls onto a textured surface like carpet.

Low velocity spatter

Blood spatter produced by a force, often resulting from actions like a drip or a light splash.

Medium velocity spatter

Blood spatter produced by a medium amount of force, typically resulting from a beating with a baseball bat or crowbar.

Round drop of blood with few spines or satellites

90 degree angle blood spatter