Bloodstain Pattern Analysis Terminology


Expiration Pattern
A bloodstain pattern resulting from blood forced by airflow out of the nose, mouth, or a wound.
Bloodstain Example - Expiration Pattern
Bloodstain Example - Expiration Pattern


This expiration pattern was generated by taking blood and mixing it with saliva in the mouth. The blood was then forced out by coughing. Any remaining blood was allowed to flow from the mouth and fall onto the target.

In the image there are several air bubbles, lighter coloured stains, and string-like stains that are not entirely linear. Note that when blood is mixed with saliva, it changes its physical characteristics.

Alternate Terminology

Bevel & GardnerSpatter - Non-linear - Impact - Expectorate
James, Kish & SuttonSpatter - Projection Mechanism - Expirated
WonderSpatter Groups - Impact - Respiratory (Expiration)
Old IABPAExpirated Blood