Blood Spatter Types Flashcards

Blood Spatter Terms and Definitions

• Angle of Impact: Acute angle between the blood drop's direction and the surface it strikes.
• Arterial Spurting Pattern: Bloodstain patterns arising from a breached artery, resulting in blood exiting under pressure.
• Back Spatter: Blood directed back towards the source of the force that caused the spatter.
• Blood Spatter Analysis: Forensic science field studying physical properties of blood and the resultant patterns from various forces.
• Bloodstain: Evidence of liquid blood contacting a surface.
• Cast-off Pattern: Bloodstain pattern created when blood is flung from a moving blood-bearing object.
• Contact Stain: Blood deposited from direct contact between two surfaces, at least one being bloody.
• Direction of Flight: Trajectory of a blood drop determined by its angle of impact and directionality angle.
• Directionality: The orientation of blood while traveling upon impacting a surface, inferred from the stain's geometric shape.
• Directionality Angle: Angle between the bloodstain's long axis and a predetermined zero degrees line on the target surface.

Blood Spatter Mechanisms

• Draw-back Effect: Blood drawn back into the barrel of a firearm through the muzzle.
• Drip Pattern: Bloodstain pattern formed when blood drips into existing blood.
• Expirated Blood: Blood expelled from the nose, mouth, or a wound due to air pressure or airflow.
• Flight Path: The trajectory of a blood drop from impact site to target surface.
• Flow Pattern: Alteration of bloodstain shape and direction due to gravity or movement of an object.
• Forward Spatter: Blood traveling in the same direction as the force causing the spatter.

Blood Spatter Classifications

• High-Velocity Impact Spatter (HVIS): Resulting from high-speed impacts (e.g., gunshots), with velocity about 100 ft/sec and drops ≤1mm.
• Impact Pattern: Bloodstain pattern from a force causing random dispersion of smaller blood drops.
• Impact Site: Location where force interacts with a blood source.
• Low Velocity Impact Spatter (LVIS): Bloodstain pattern from low-speed impacts, velocity up to 5 ft/sec with drops sized 4-6mm.
• Medium Velocity Impact Spatter (MVIS): Pattern from medium-speed impacts, often due to beating/stabbing, at about 25 ft/sec with drops of 1-4mm.

Additional Blood Spatter Insights

• Misting: Blood reduced to a fine spray due to applied energy or force.
• Parent Drop: Blood drop that gives rise to satellite spatter.
• Passive Drop (Bleeding): Bloodstain formed solely by the force of gravity.
• Point (Area) of Convergence: 2D common point where trajectories of multiple blood drops can be retraced.
• Point (Area) of Origin: 3D common point where blood drop trajectories converge.
• Projected Blood Pattern: Bloodstain pattern from blood released under pressure, as seen in arterial spurting.
• Satellite Spatter: Small droplets surrounding a blood drop or pool, resulting from the impact on the target surface.
• Spatter: Blood dispersed as a result of force dynamics.