Bloodstain Pattern Analysis Terms

Accompanying Drop

A small blood drop produced as a by-product of drop formation

Altered Bloodstain

A bloodstain or pattern with characteristics that indicate a physical change has occurred. Dilution, diffusion, cold

Angle of Impact

the acute angle at which a blood drop strikes a target; relative to the plane of the target

Area of Convergence

The area of intersection in two-dimensions created by lines drawn through the long axis of individual stains; most often associated with an impact pattern.

Area of Origin

The area in three-dimensions of a blood source most often associated with an impact pattern.

Back Spatter Pattern

A bloodstain pattern resulting from blood drops that travel in the opposite direction of the external force applied; often associated with entrance wound of a gunshot.

Blood Clot

A gelatinous mass formed as a complex mechanism involving red cells, fibrinogen, platelets, and other clotting factors.

Bloodstain

A spot or stain made by blood

Bloodstain Pattern

A characteristic grouping or distribution of bloodstains which may indicate the manner in which the pattern was deposited.

Bubble Ring

A ring in a bloodstain that results from an air bubble

Cast-Off Pattern

A bloodstain pattern resulting from blood drops released from a bloodied object in motion

Cessation Cast-Off Pattern

A bloodstain resulting from blood drops released from a bloody object as it suddenly stops

Directionality

The path of travel of a blood drop indicated by the stain’s shape

Directional Angle

The angle between the long axis of a bloodstain and a reference line on the target

Drip Pattern

A bloodstain pattern resulting from liquid dripping into liquid, where at least one liquid is blood.

Drip Stain

A bloodstain resulting from the formation and falling of a drop of blood.

Drip Trail

A series of bloodstains that result from blood dripping from a source that is in horizontal motion.

Edge Characteristics

The physical characteristics at the periphery of a bloodstain that may be described as spines, scalloping, smooth, or irregular margins.

Expirated Pattern

A bloodstain pattern resulting from blood being forced out of the nose, mouth, or a wound by air pressure

Flow Pattern

A bloodstain pattern resulting from the movement of a volume of blood on a surface due to gravity and/or movement the target

Forward Spatter Pattern

A bloodstain pattern resulting from blood drops that travel in the same direction as the external force applied; often associated with the exit wound of a gunshot

Impact Pattern

A bloodstain pattern resulting from an object striking liquid blood

Insect Stain

Bloodstains produced as the result of insect activity

Mist Pattern

A bloodstain pattern resulting from blood reduced to a spray of localized micro drops as a result of the force applied; often associated with gunshot injuries

Parent Stain

The bloodstain from which wave cast-off or satellite bloodstains originate

Pool

An accumulation of liquid blood on a surface

Projected Pattern

A bloodstain pattern resulting from the ejection of a volume of blood under pressure; often associated with a vascular breach

Satellite Stain

Smaller bloodstains that originate during the formation of the parent stain as a result of blood impacting a surface

Saturation Pattern

A bloodstain resulting from the accumulation of liquid blood in an absorbent material

Serum Stain

The stain resulting from the liquid portion of the blood that separates after coagulation.

Skeletonized Stain

A bloodstain which has been altered after a period of drying leaving observable peripheral characteristics of the original stain

Spatter Stains

Bloodstains resulting from blood drops distributed through the air due to an external force applied to a source of liquid blood

Splash Pattern

A bloodstain pattern resulting from a volume of liquid blood that falls or spills onto a surface

Swipe Pattern

A bloodstain pattern resulting from the transfer of blood from a bloodied surface onto another surface, with characteristics that indicate relative motion between the two surfaces

Target

A surface onto which blood has been deposited

Transfer Pattern

A bloodstain pattern resulting from contact between a wet bloody surface and another surface

Void

The absence of blood in an otherwise continuous bloodstain pattern

Wave Cast-Off Pattern

A satellite bloodstain that originates from a parent bloodstain due to the wave-like action of the liquid that occurs when the parent drop strikes a surface at an angle

Wipe Pattern

A bloodstain pattern resulting from an object moving through a pre-existing bloodstain altering the original stain

Ghosting

Similar to a void