Glossary of Key Bloodstain Pattern Analysis Terms

Drip Stain

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

Mist Pattern

a bloodstain pattern resulting from blood reduced to a spray of micro-drops as a result of high velocity force applied

Splash

pattern created when a volume of blood in excess of 1mL strikes a surface at a low to medium velocity

Area of Convergence

the location of the blood surface source determined by drawing lines from the various blood droplets to the point where they intersect - 2D

Clot

a mass of blood and other contaminants caused through clotting mechanisms

Front Spatter

blood that is directed toward the direction of the force

Wipe

pattern created when a secondary target moves through an existing wet blood stain on some other object

Back Spatter

refers to blood exiting the entrance wound in the direction opposite the impact

Medium Velocity Spatter

an impact spatter created by a force traveling at 5 to 25 feet per second producing drops with a diameter between 1 and 3 millimeters

Spines

the pointed edges of a stain that radiate out to form the spatter

Impact Site

usually the point on the body that received the blow or applied force, from which the blood was shed

Target

the surface where the blood ends up

Cast-Off Stains

blood that has been thrown from a secondary object (weapon or hand) onto a target other than the impact site

Area of Origin

the area in space where the blood spatter came from - 3D

Angle of Impact

the angle at which a blood droplet strikes a surface

Arterial Spurts

large patterns created under pressure, but with less volume and usually more distinctive evidence of blood pressure rising and falling

Blood into Blood Patterns

characteristics patterns present when blood drips into standing, wet blood

Expiratory Blood

blood which is spattered onto a target, as a result of breathing; typically, this occurs when an injury is sustained to the throat, mouth, or airway

Flow Pattern

a bloodstain pattern formed by the movement of small or large amounts of blood as a results of gravity’s pull

Impact Spatter

bloodstains created from the application of force of energy to the area where the blood is, projecting drops of blood outward from the source

Low Velocity Spatter

an impact spatter created by a force traveling at 5 ft per second or less producing drops with a diameter greater than 3 mm

High Velocity Spatter

an impact spatter created by a force traveling at 100 ft per second or faster producing drops with a diameter less than 1 mm

Pattern Drop

the droplet from which satellite spatter originated

Projected Blood

blood under pressure that strikes a target

Satellite Spatters

small drops of blood that break off from the parent spatter when the parent droplet strikes a target surface

Transfer Pattern

the pattern created when a wet, bloody object comes in contact with a target surface, leaving a pattern that has the features of the object making it useful for identifying the object

Shadowing/Ghosting/Void

a pattern that helps to place an object or body in the scene; normally, the area in question lacks blood even though areas surrounding it show blood

Skeletonized Stain

the pattern left when an object moves through a partially dried stain, removing part of the blood, but leaving the outline of the stain intact

Swipe

the transfer of blood onto a target surface by a bloody object that is usually moving laterally