Passive Drip
Definition
A stain formed when blood falls from a source under gravity alone. The resulting drop is roughly circular; its diameter correlates with fall height and target-surface roughness.
- Cause
- Gravity alone, no external force
- Shape
- Roughly circular
- Correlates with
- Fall height and surface roughness
- Category
- Passive bloodstain pattern
Common questions
How does a passive drip differ from impact spatter?+
A passive drip results only from gravity acting on a static or slow-moving source, producing a roughly circular stain, while impact spatter results from an external force striking a blood source and produces elongated, directional droplets.
What can the diameter of a passive drip tell an analyst?+
A larger diameter generally suggests a greater fall height, though the relationship is not perfectly linear and is also shaped by the texture and absorbency of the target surface.
Related terms
- Bloodstain Pattern Analysis (BPA)
- The scientific discipline that examines the size, shape, distribution, and location of bloodstains to reconstruct the events that produced them, addressing questions...
- IABPA
- The International Association of Bloodstain Pattern Analysts, founded 1983, which sets training standards and accreditation criteria for BPA specialists.
- Presumptive Test
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- Projected Pattern
- A pattern produced when blood is expelled under pressure or force exceeding gravity, as in arterial spurting, impact spatter, or cast-off from...
- Transfer Stain
- A stain deposited when a wet, blood-bearing object contacts a surface and leaves an impression. Shoe soles, hands, fabric, and tools can...