Blood Spatter Evidence

The different kinds of blood spatters
Angle of Impact
the acute angle formed between the direction of a blood drop and the plane of the surface it strikes
Arterial Spurting (or gushing) Pattern
bloodstain pattern(s) resulting form blood exiting the body under pressure from a breached artery
Back Spatter
blood directed back toward the source of energy for force that caused the spatter
Blood Spatter Analysis
a field of forensic science that deals with the physcial properties of blood and the patterns produced under different conditions as a result of various forces applied to the source of the blood
evidence that liquid blood has come into contact with a surface
Cast-off Pattern
a bloodstain pattern created when blood is released or throw from a moving blood-bearing object
Contact Stain
blood deposited from direct contact between two surfaces, at least one of which is bloody
Direction of Flight
the trajectory of a blood drop, which can be established by it's angle of impact and directionality angle
the direstion the blood was traveling when it hit the target surface; investagators can usually establish this if a blood drop's flight from the geometric shape of its bloodstain
Directionality Angle
the angle between the long axis of a bloodstain and a predetermined line on the plane of the target surface that represents 0 degrees
Draw-back Effect
blood in the barrel of a firearm that has been drawn backward into the muzzle
Drip Pattern
a bloodstain pattern that results from blood dripping into blood
Expirated Blood
blood that is blown out of the nose, mouth, or a wound as a result of air pressure or air flow, which is the propelling force
Flight Path
the path of the blood drop as it moves though the space, from the impact site to the target
Flow Pattern
a change in the shape and direction in the bloodstain due to the influence of gravity or movement of the object
Forward Spatter
blood that travels in the same direction as the source of energy or force that caused the spatter
High-velocity Impact Spatter (HVIS)
a bloodstain pattern caused by a highspeed impact or a force to a blood source such as that produced by gunshot; velocity may be 100ft/sec, generally forming drops less than or equal to 1mm
Impact Pattern
bloodstain pattern created when blood recieves a blow or force resulting in the random disperse of smaller drops of blood
Impact Site
the point where force meets a blood source
Low-velocity Impact Spatter (LVIS)
a bloodstain pattern caused by a low-speed impact or force to a blood source; velocity may be up to about 5ft/sec with drop size of 4 to 6mm
Medium-velocity Impact Spatter (MVIS)
a bloodstain pattern caused by a medium-speed impact or force to a blood source; a beating or stabbing typically causes this type of spatter, and velocity may be about 25ft/sec with a stain generally of 1 to 4mm
blood that has been reduced to a fine spray as a result of the energy or force applied to it
Parent Drop
a drop of blood that casts off a wave or satellite spatter
Passive Drop (bleeding)
bloodstain drop(s) created or formed by the force of gravity acting alone
Point (area) of Convergence
the common point (area), on a two dimensional surface, over which the directionality of several blood drops can be retraced
Point (area) of Origin
the common point (area), in a three dimensional space, to which the trajectories of several blood drops can be replaced
Projected Blood Pattern
a bloodstain pattern produced by blood released under pressure, such as arterial spurting, as opposed to an impact
Satellite Spatter
small droplets of blood distributed around a drop or pool of blood as a result of the blood hitting the target surface
blood that has been dispersed as a result of force applied to it's source; the pattern will vary depending on the force that created it
the pointed or elongated stains that radiate from the central area of a bloodstain
Swipe Pattern
the transfer of blood from a moving source onto an unstained surface; the direction of travel may be determined by the feathered edge
the surface on which blood has been deposited
Transfer or Contact Pattern
a bloodstain pattern created when a wet, bloody surface comes in contact with a second surface; a recognizable image of all or a portion of the original surface may be observed in the pattern
an absence of stains in an otherwise continuous bloodstain pattern, like a reverse shadow
Wipe Pattern
a bloodstain pattern created when an object moves through an existing stain, removing it or changing its appearence