What is Swgstain?
Introduction. The Scientific Working Group on Bloodstain Pattern Analysis (SWGSTAIN) comprises bloodstain pattern analysis (BPA) experts from North America, Europe, New Zealand, and Australia.
What is an Expirated blood pattern?
Expirated Blood — Blood that is blown out of the nose, mouth, or a wound as a result of air pressure and/or air flow which is the propelling force. Medium Velocity Impact Spatter (MVIS) — A bloodstain pattern caused by a medium velocity impact/force to a blood source. A beating typically causes this type of spatter.
What are the steps in the process of bloodstain characterization?
Bloodstain analysts use established scientific methods to examine bloodstain evidence at a crime scene including information gathering, observation, documentation, analysis, evaluation, conclusion and technical (or peer) review.
What is a taxonomic classification system for bloodstains?
In Bloodstain Pattern Analysis: With an Introduction to Crime Scene Reconstruction, Tom Bevel, and Ross Gardner use a taxonomic classification system where the main categories are The Spatter Family, The Non-Spatter Family, and Complex Patterns.
What is the difference between a spine and satellite drop?
Satellite Spatters – Small drops of blood that break of from the parent spatter. Spines – The pointed edges of a drop.
What is the point of origin in forensics?
The origin of a blood spatter in a two-dimensional configuration can be established by drawing straight lines through the long axis of several individual bloodstains. The intersection or point of convergence of the lines represents the origin point.
What are the 4 types of passive bloodstains?
Passive. a. formed from the force of gravity acting alone. b. subdivided (drops, drip patterns, pools, clots) c. oozing or gushes from the body, dripping finger or arm, drops from a knife.
What are the 6 types of blood spatter patterns?
There are seven bloodstain categories: (1) passive bloodstain; (2) projected bloodstains; (3) impact spatter; (4) cast-off bloodstains; (5) arterial gush or spurt bloodstains; (6) wipe bloodstain patterns; and (7) transfer bloodstains.
What are the 3 types of blood spatter?
Bloodstains are classified into three basic types: passive stains, transfer stains and projected or impact stains.
How is the angle of impact calculated?
Calculate the angle of impact with the following equation: “i = asin (w/l).” Replace “w” with the length of the minor axis and “l” with the length of the major axis. “Asin” is the arcsin or inverse sine function and is available on most calculators.
What is a passive stain?
Passive stains include drops, flows and pools, and typically result from gravity acting on an injured body. Transfer stains result from objects coming into contact with existing bloodstains and leaving wipes, swipes or pattern transfers behind such as a bloody shoe print or a smear from a body being dragged.