Bloodstain Pattern Analysis

Documentation of Bloodstain Patterns helps why?

Determines who shed blood

Shows possible mechanisms of bloodstain deposition

Evaluate sequence of events

Disputes or aids eyewitness testimonies

Passive Blood Drops

Teardrop shape as gravity pulls it downward. Once separated, it becomes a sphere that ocillates as it falls

Proper Measurement of a bloodstain

Dont include spatter or spine

Area of convergence

Using multiple impact angles to determine where the blood converges

Pattern Recognition and Classifications

Impact Pattern

Cast-off Pattern

Expiration Pattern

Projected Pattern

Swipe

Wipe

Drip Trail

Drip Pattern

Impact Pattern

A bloodstain pattern from an object striking liquid blood

Cast-off Pattern

Bloodstain pattern resulting from blood drops released from an object due to its motion

Expiration Pattern

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

Projected Pattern

Bloodstain pattern from the ejection of blood under hydraulic pressure usually from a breach in the circulatory system

Swipe Stain

Bloodstain pattern from a transfer of blood from a blood bearing surface onto another surface usually done with motion

Wipe Stain

Bloodstain pattern resulting from an object moving through a preexisting wet bloodstain

Drip Pattern

A bloodstain pattern resulting from a liquid that was dripped into another liquid, one of them bring blood

Drip Stain

Bloodstain pattern resulting from a falling drop formed due to gravity

Drip Tail

A series of drip stains showing movement of the source

Splash Pattern

Bloodstain pattern from a large volume of liquid blood falling onto a surface

Transfer Stain

Bloodstain pattern resulting from contact between a blood-bearing surface and another surface

Flow Stain

Bloodstain pattern resulting from the movement of a volume of blood on a surface due to gravity

Perimeter Stain

An altered stain consisting of its edge characteristics, the central area having been partially or entirely removed

Void

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

Chemical Enhancement of Latent Bloodstains

LCV - turns hidden blood into a dark purple color