Bloodstains are classified into three basic types: passive stains, transfer stains and projected or impact stains.
What are the 6 patterns of blood spatter?
1902, Dr. John Glaister described 6 patterns: a.
What do blood stain patterns determine?
Bloodstain pattern analysis is the use of the bloodstain size, shape, and distribution patterns found at a crime scene in order to determine the bloodshed event(s). Bloodstain patterns reveal not “who” but “what and how” with regard to the bloodshed event.
What is the most common blood stain pattern?
Impact spatter
Impact spatter is the most common bloodstain pattern type in a crime scene. It occurs when an object hits a source of blood. In impact blood spatter patterns, blood is often circular and not elongated. There are two types of impact spatter, back spatter and forward spatter.
How do you identify blood stains?
Luminol is often combined with hydrogen peroxide to react with the heme groups in blood, producing a bright blue glow, known as chemiluminescence. This glow allows crime scene technicians to detect blood that has dried on surfaces or to detect blood that someone tried to clean from a surface.
What is a transfer pattern?
A transfer pattern is a pattern that forms when a wet, bloody surface comes in contact with a second surface. A recognizable image of all or part of the object that caused the pattern can sometimes be observed in the pattern.
What is a peripheral ring stain?
Perimeter Stain – An altered stain that consists of the peripheral characteristics of the original stain. Plasma – The clear, yellowish fluid portion of blood. Spatter Stain – A bloodstain resulting from a blood drop dispersed through the air due to an external force applied to a source of liquid blood.
What is the pattern of arterial spurting?
Arterial Spurting (or gushing) Pattern — Bloodstain pattern(s) resulting from blood exiting the body under pressure from a breached artery. Directionality of a blood drop’s flight can usually be established from the geometric shape of its bloodstain.
How important is blood pattern analysis in a criminal investigation?
Bloodstain pattern analysis provides important forensic information about the crime under investigation; it tells what happened. Every effort must be made to preserve the crime scene until the bloodstain evidence has been investigated.
What does blood stain analysis examine?
Bloodstain pattern analysis (BPA) is the interpretation of bloodstains at a crime scene in order to recreate the actions that caused the bloodshed. Analysts examine the size, shape, distribution and location of the bloodstains to form opinions about what did or did not happen.
What is void pattern?
Void patterns, or the absence of blood within an otherwise continuous bloodstain pattern, have been traditionally used by analysts for a number of purpos- es. Void patterns may also re- veal the precise position of clothing on an individual at the time of the bloodletting incident.
