SWGSTAIN terms

Scientific Working Group on Bloodstain Pattern Analysis (SWGSTAIN)

Governing body of Blood Pattern Analysis, providing a professional forum for practitioners to discuss and evaluate methods, techniques, protocols, quality assurance, education, and research worldwide.

Passive stains

Bloodstains and patterns from free-falling drops or blood subjected to gravity, air resistance, and surface nature.

Transfer Stain

Bloodstain formed when a bloodied surface contacts another surface.

Impact Stain

Bloodstain patterns from an object striking liquid blood, showing differently based on the force exerted.

Area of Origin

The space in three dimensions used to determine the location of the spatter-producing event by utilizing the trajectories of spatter.

Angle of Impact

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

Area of Convergence

The area containing the intersections generated by lines drawn through the long axes of individual stains, indicating the location of the blood source in two dimensions.

Backspatter Pattern

A bloodstain pattern resulting from blood drops traveling in the opposite direction of the external force applied, associated within an entrance wound created by a projectile.

Blood Clot

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

Bubble Ring

An outline within a bloodstain resulting from air in the blood.

Cast-Off Pattern

A bloodstain pattern resulting from blood drops released from an object due to its motion, showing as an arch with somewhat uniformed blood droplets until the tail end where there is less blood.

Directionality

The characteristic of a bloodstain indicating the direction blood was moving at the time of deposition.

Drip Pattern

A bloodstain pattern resulting from a liquid that dripped into another liquid, at least one of which was blood.

Drip Stain

A bloodstain resulting from a falling drop that formed due to gravity.

Drip Trail

A bloodstain pattern resulting from the movement of a source of drip stains between two points.

Edge Characteristic

A physical feature of the periphery of a bloodstain.

Expiration Pattern

A bloodstain pattern resulting from blood forced by airflow out of the nose, mouth, or a wound.

Flow Pattern

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

Forward Spatter Pattern

A bloodstain pattern resulting from blood drops that traveled in the same direction as the impact force.

Insect Stain

A bloodstain resulting from insect activity.

Mist Pattern

A bloodstain pattern resulting from blood reduced to a spray of micro-drops as a result of the force applied.

Parent Stain

A bloodstain from which a satellite stain originated.

Perimeter Stain

An altered stain consisting of the peripheral characteristics of the original stain.

Pool

A bloodstain resulting from an accumulation of liquid blood on a surface.

Projected Pattern

A bloodstain pattern resulting from the ejection of a volume of blood under pressure, typically from a punctured artery.

Satellite Stain

A smaller bloodstain that originated during the formation of the parent stain as a result of blood impacting a surface.

Saturation Stain

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

Serum Stain

The stain resulting from the liquid portion of blood (serum) that separates during coagulation.

Spatter Stain

A bloodstain resulting from a blood drop dispersed through the air due to an external force applied to a source of liquid blood.

Swipe Pattern

A bloodstain pattern resulting from the transfer of blood from a blood-bearing surface onto another surface, indicating relative motion between the two surfaces.

Void

An absence of blood in an otherwise continuous bloodstain or bloodstain pattern.

Wipe Pattern

An altered bloodstain pattern resulting from an object moving through a pre-existing wet bloodstain.