IAI CP2 key terms

The reconstruction discipline that examines the size, shape, distribution, and orientation of blood deposits to infer the physical events that produced them, such as impact, projection, or contact.

A visible deposit of blood on a surface whose geometry records how the blood was deposited, providing physical evidence about motion, force, and position of source and target.

A dispersion of small droplets thrown outward when force is applied to liquid blood, typically traveling away from the point of applied force and striking surfaces at various angles.

A pattern of very fine droplets, generally under about 1 mm, associated with high-energy events such as gunshot wounds, explosions, or powered machinery, often appearing as a mist-like deposit.

A pattern of droplets roughly 1 to 4 mm across produced by blunt-force or similar moderate-energy impact, commonly thrown outward from the point of force application.

A pattern of relatively large droplets, generally over about 4 mm, formed when low energy, such as dripping or minor force, deposits blood with little atomization.

A linear series of bloodstains thrown from a bloodied object, such as a weapon, as it swings; the stains track the arc and direction of the swing and can indicate the number of blows.

A pattern produced when blood exits a breached artery under pressure, often appearing as repeating, arc-shaped lines or spurts that record the victim's movement and pulse.

Blood forced from the nose or mouth by exhaled air, producing fine droplets often mixed with saliva or mucus, sometimes with bubble rings, and typically directed away from the face.

Blood projected backward toward the source of force, such as from a gunshot entrance wound or a blunt impact, and often deposited on the weapon, shooter, or nearby surfaces.

Blood projected in the same direction as the applied force, exiting an injury or object and traveling away from the source, commonly seen with gunshot exit wounds.

A bloodstain formed when blood falls under gravity alone onto a surface, typically circular on horizontal surfaces and elongated on inclined surfaces, without added force.

A blood deposit created by gravity or capillary action without applied force, including drops, pools, and flows, reflecting the natural movement of blood after it leaves the body.

A stain created when a blood-bearing object contacts a surface and leaves an impression, whose shape may reflect the object's contours, texture, or motion.

A transfer stain formed by direct, mostly stationary contact between a bloodied object and a surface, often preserving the shape of the object or body part.

A transfer stain left when a bloodied object moves across a surface, showing direction of travel through feathering or a tapering edge, without necessarily cleaning the surface.

A stain produced when an object moves through wet blood on a surface, altering or removing the original deposit and often leaving streaks that record the wiping motion.

A trail formed when liquid blood moves across a surface under gravity, following contours and pooling in low areas, useful for inferring surface orientation and body position.

An accumulation of liquid blood in a low area or on a level surface, whose outline and depth can indicate volume, surface tilt, and elapsed time before drying.

The primary bloodstain from which smaller satellite droplets originate, used to relate a group of stains to a single deposition event and impact.

Small droplets thrown from a parent stain on impact with a surface, landing around the parent and indicating the force and angle of that initial deposition.

Bloodstains produced when blood is propelled by an external force other than gravity, such as pressure, coughing, or arterial flow, rather than falling passively.

A very fine, diffuse deposit of tiny droplets, often from high-energy events or expirated blood, appearing as a haze and useful for associating a surface with an energetic source.

The acute angle between the path of a blood droplet and the target surface at contact, estimated from stain shape and central to reconstructing the droplet's flight path.

A bloodstain whose elongated shape results from an angled impact, with the long axis aligned to the droplet's travel direction and the width-to-length ratio used to estimate impact angle.

The horizontal heading of a droplet before impact, inferred from stain shape, spine orientation, and tail features, allowing reconstruction of the droplet's path.

The two-dimensional region on a surface where lines drawn through the long axes of related stains intersect, approximating the horizontal position of the blood source.

The three-dimensional location in space from which related droplets traveled, derived from convergence lines combined with impact angles and stringing or trigonometry.

A reconstruction technique in which strings or rods are anchored at stains and aligned with their trajectories to visualize convergence and the three-dimensional area of origin.

A narrow projection extending from a bloodstain in the direction of droplet travel, formed when the droplet splashes forward on impact and useful for reading direction.

A cast-off pattern produced when a bloodied object stops moving, depositing blood in a line that can indicate where and how the swing ended.

A cast-off pattern created during the active arc of a swing, with stains aligned along the swing path and spacing that can suggest the number of blows delivered.

An absence of bloodstaining in an otherwise stained area, indicating that an object or person blocked deposition and was present at the time the pattern formed.

The clean area left when a person or object intercepts blood that would otherwise have reached a surface, preserving an outline of the blocker's position.

A group of passive drops falling from a bloodied object or person onto a surface, often forming a trail whose spacing reflects movement and dripping rate.

A bloodstain in which the dried edge remains while the center has been removed or flaked away, sometimes indicating a later cleaning or secondary contact.

The systematic recording of stains through photography with scale, sketches, measurements, and notes, preserving pattern evidence for review and court presentation.

The process of using documented bloodstain patterns, together with scene and autopsy information, to infer the sequence and mechanics of events that produced the bloodshed.