What defines a passive bloodstain?
- Passive. a. formed from the force of gravity acting alone. b. subdivided (drops, drip patterns, pools, clots) c. oozing...
- Transfer. a. wet bloody surface comes in contact with a secondary surface. b. wipe, smudge, swipe or smear. c.
- Projected blood spatter.
What is an example of passive bloodstain?
Passive Bloodstains. Examples are swipes, footprints, and handprints (see graphic C). A swipe bloodstain pattern (see graphic D) is when a bloodied object contacted the surface and deposited blood in a swiping motion. It should not be confused with a wipes bloodstain pattern which is a subcategory of altered bloodstains.
What is a bloodstain?
• Bloodstains can occur on a variety of surfaces. The type of appearance of the resulting spatter. or regular circular shape. shaped stain with rough or jagged edges.
What are transfer bloodstains?
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. Click to see full answer. Considering this, what are the 4 types of passive bloodstains?
What is the difference between passive and transfer stains?
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. Click to see full answer.
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.Transfer. a. wet bloody surface comes in contact with a secondary surface. b. wipe, smudge, swipe or smear. c. ... Projected blood spatter.
What defines a passive bloodstain quizlet?
passive drop (bleeding) bloodstain drops created or formed by the force of gravity acting alone.
What is the difference between passive and projected bloodstains?
Passive bloodstains are those stains created by the force of gravity. A projected stain occurs when some form of energy has been transferred to a blood source. A transfer or contact stain is produced when an object with blood comes in contact with an object or surface that does not have blood.
What is the only force acting on a passive blood stain?
Terms in this set (18) Passive bloodstains are created or formed by the force of gravity acting alone.
What are passive patterns How can they be formed?
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.
What is a passive drop and what is its shape?
Passive drops will vary in shape and size depending on the volume of blood and the surface texture, but will generally be circular. A bloodstain pattern which results from blood dripping into blood.
What qualifies as a projected bloodstain?
Projected bloodstains are created when an exposed blood source is subjected to an action or force, greater than the force of gravity. The size, shape, and number of resulting stains will depend, primarily, on the amount of force utilized to strike the blood source.
What size are passive blood drops?
High speed images of the falling drops were captured. The primary blood drop size ranged from 4.15±0.11 mm up to 6.15±0.15 mm (depending on the object), with the smaller values from sharper objects.
What is the relationship between passive blood drop diameter and height?
The height from which blood falls is directly proportional to the diameter of the blood stain.
What four forces act on a blood droplet?
Blood SpatterViscosity.Surface Tension.Droplet Flight Dynamics.The 4 Phases of Impact.Phase 1: Contact and Collapse.Phase 2: Displacement.Phase 3: Dispersion.Phase 4: Retraction.More items...
What information is obtained from a proper bloodstain pattern analysis?
The following Information may be obtained from a. proper Bloodstain Pattern Analysis: 1. Distance from the blood source to the target. 2. Direction of travel and impact angles. 3. Nature of the force used to cause the bloodshed.
What is bloodstain pattern analysis?
Bloodstain Pattern Analysis: is the examination of the shapes, an interpretation of the physical events that gave rise to their origin. 1. Distance from the blood source to the target. 2. Direction of travel and impact angles. 3. Nature of the force used to cause the bloodshed. 4.
What is the tail of a bloodstain?
Typically, the tail of a bloodstain will provide information regarding the directionality of a bloodstain pattern, which ultimately provides information during reconstruction activities on where the bloodshed occurred.
Why do bloodstains fall?
As compared to passive bloodstain patterns, which typically fall as drops as a result of gravity, spatter bloodstain patterns often arise due to additional force or motion to the bleeding source.
How does BPA help reconstruction?
One of the first ways in which BPA assists during reconstruction activities is through determining what type of bloodstain pattern is present. In general, these patterns can be divided into three different categories including passive drop, spatter, and special bloodstain configuration patterns.
What is blood stain pattern analysis?
What is Bloodstain Pattern Forensic Analysis? In general, bloodstain pattern analysis (BPA) refers to the collection and subsequent forensic analysis investigation of the size, shape, and distribution patterns of bloodstains found at a crime scene. Image Credit: akepong srichaichana/Shutterstock.com.
What is accurate BPA?
An accurate BPA will not only involve the procurement of information regarding a single stain but will also consist of appropriate documentation of the entire surrounding area where the bloodstain was identified.
What causes blood to drop spherical?
Passive bloodstain patterns. As blood drops from its source, the surface tension of this liquid causes these drops to be s pherical. As the distance between the blood source and the target source increases, the diameter of the bloodstain will also increase until the terminal velocity of the blood drop is reached.
What are the components of blood?
Within the plasma, which is the liquid component of blood, exists various proteins, electrolytes, lipids, and glucose. Under normal conditions, the components of blood will not break apart; however, the application of external forces can result in the deposition of blood into several different bloodstain patterns.
What is the second basic category of bloodstains?
The second basic category of bloodstains is “spatter .” Spatter bloodstain patterns are blood patterns produced as a result of having received additional force or motion than gravity. It has more force than passive drops/drips.
What is the tail of a bloodstain?
The “tail” or wave castoff of the bloodstain generally points to the direction of travel of the blood drop. The direction of travel and the angle of impact are referred to as the directionality of a bloodstain pattern. The directionality of a bloodstain will be used for reconstructing where the bloodshed occurred.
What is SWGStain forensics?
SWGStain was tasked with addressing current issues that affect the forensic sciences and the impact of those issues on the discipline of bloodstain pattern analysis. SWGStain was also tasked with developing recommended guidelines for training, quality assurance, and research in bloodstain pattern analysis.
What is the IABPA?
The International Association of Bloodstain Pattern Analysts (IABPA), founded in 1983, is dedicated to advancing bloodstain pattern analysis as a forensic science. The IABPA publishes an online journal quarterly and hosts an annual training conference that is attended by bloodstain analysts from around the world.
How long has blood stain analysis been around?
The roots of bloodstain pattern analysis can be traced back more than 100 years. As the historian for the International Association of Bloodstain Pattern Analysts (IABPA), Herbert Leon MacDonnell has found literature references to bloodshed characteristics dating back to the 1500s.
What is blood stain pattern analysis?
Bloodstain pattern analysis (BPA) conducted by scientists using deductive reasoning, experimentation, and a complete understanding of the crime scene can inform courts and juries about the details of a crime.
What causes blood to spherically form?
The fluid dynamics of dropping blood are responsible for the stains or patterns produced. The surface tension of the liquid blood causes the blood drops produced from a blood source to be spherically shaped. Blood drops are much more viscous than water and it possesses an adhesive quality that provides for small amounts of blood to adhere to most surfaces and begin drying upon contact.
