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 are the 4 types of passive bloodstains?
In this manner, 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 type of blood spatter would a gunshot produce?
Forward spatter from a gunshot wound will typically form smaller droplets spread over a wide area, while impact spatter will form larger drops and be more concentrated in the areas directly adjacent to the action. Left: large volume blood stain. Right: impact spatter pattern. Left: passive bloodstains.
what is a passive blood stain?
Passive stains result from an action other than a directed force to a blood mass. Blood dripping, contact with bloody objects, which can further be categorized as contact patterns, drip patterns, drip trails, blood pools or flows or blood clots.
How does a blood droplet form?
Medium- and high-velocity spatters When a force ruptures the skin and impacts blood directly, it breaks up into droplets that land on surfaces in a specific spatter pattern. Weapons produce different spatter patterns depending on the velocity at which they strike.
What does the size of a blood droplet depend on?
As a blood drop falls perpendicular to a surface it maintains a spherical form until impacting. The size and appearance of this stain will depend on a number of factors. A greater force will typically produce smaller droplets, with the density of blood drops decreasing moving further away from the initial blood source. You may also read,
What is the only force acting on a passive blood stain?
gravity Check the answer of
What causes low velocity blood spatter?
Low Velocity Impact Spatter (LVIS) — A bloodstain pattern that is caused by a low velocity impact/force to a blood source. Projected Blood Pattern — A bloodstain pattern that is produced by blood released under pressure as opposed to an impact, such as arterial spurting.
What is a transfer pattern?
A transfer bloodstain or bloodstain patterns is created when a wet, bloody surface contacts another surface. A recognizable image of all or a portion of the original surface may be observed in the pattern. Transfer bloodstain can be further subdivided into: contact bleeding, swipes or wipes. Read:
How do you determine the origin of blood spatter?
By measuring the width and length of a single drop of blood, you can determine the angle of impact. By using the Law of Tangents, you can calculate the height from which the blood fell, or the point of origin for the blood.
What are the four stages of blood droplet stain?
Terms in this set (4) Contact/collapse. Droplet hits the object. Displacement. Slight dimples and spines begin to form based on the irregularities on the impact surface. Dispersion. Most of the volume of the blood is forced to the rim. Retraction.
How does surface affect blood spatter?
The texture of the target surface upon which a drop of blood falls affects the size and shape of the bloodstain pattern. Hard, nonporous surfaces will produce circular stain patterns that have smooth edges, but softer, porous surfaces will produce spatter stains that are scalloped or have rough edges.
How do you find the angle of impact of a blood drop?
Angle of Impact Measure the length and width of the splatter. Divide the width of the splatter by its length. Determine the arcsin of that number, typically using a calculator with an arcsin function.
What is the difference between a wipe and a swipe?
As verbs the difference between swipe and wipe is that swipe is to steal or snatch while wipe is to move an object over, maintaining contact, with the intention of removing some substance from the surface (cf rub).
What factors affect blood spatter patterns?
Bloodstain Characteristics Many factors affect the size and shape of the blood drops. In addition to droplet volume, distance of fall and the blood source surface characteristics, other factors affect the size, shape and appearance of the bloodstains.
