The shape and size of the puddle depends on
the amount of liquid, the height of the container
, and whether you spill on carpet, wood, linoleum or some other surface.
What is the shape of a drop produced from a passive drop?
Passive drops will vary in shape and size depending on the volume of blood and the surface texture, but will generally be
circular
.
What are the irregular shapes that form around the edge of a blood drop called?
If a blood drop is on fabric, the center will
skeletonize
(Form a dark irregular shape).
What determines the edge characteristics of blood?
Edge Characteristic –
A physical feature of the periphery of a bloodstain
. Expiration Pattern – A bloodstain pattern resulting from blood forced by airflow out of the nose, mouth, or a wound. … Mist Pattern – A bloodstain pattern resulting from blood reduced to a spray of micro-drops as a result of the force applied.
What are the 3 different types of blood spatter patterns?
Bloodstains are classified into three basic types:
passive stains, transfer stains and projected or impact stains
.
What shape does a passive drop of blood at a 90 degree angle have?
When a droplet of blood strikes a surface perpendicular (90 degrees) the resulting bloodstain will be
circular
. Blood that strikes a surface at an angle less than 90 degrees will be elongated or have a tear drop shape.
What are the six patterns of blood spatter?
- 1902, Dr. John Glaister described 6 patterns: a. …
- circular drops. b. arterial gusheswalls or ceilings produced by.
- pumping action of the heart. c. splashesshaped like exclamation points;аused to.
- d. smearsleft when victim or suspect touches surface. e. …
- smears. f. poolsperson remains in one place bleeding heavily.
What are the 4 types of passive bloodstains?
- Passive Bloodstain. Passive Bloodstain on a rough surface (such as wood or concrete)
- Projected Bloodstain. Projected Bloodstain, possibly a Cast-Off Pattern or a HVIS.
- Transfer Bloodstain.
What is a passive blood drop?
Passive Drop (Bleeding) — Bloodstain drop(s)
created or formed by the force of gravity acting along
. … Projected Blood Pattern — A bloodstain pattern that is produced by blood released under pressure as opposed to an impact, such as arterial spurting.
What two forces act on a falling drop of blood?
The spherical shape is caused by
the surface tension
of the blood. Surface Tension causes the blood drop to pull itself in; both horizontally and vertically. The blood drop will settle into a spherical shape, as a result of the surface tension.
What does it mean to say blood is cohesive?
Blood travels in spherical drops because of surface tension,
the tendency of liquids to minimize surface area because their molecules are attracted to one another
— it’s cohesive [sources: DLS, Rosina et al.]. … Blood dries over time.
Does Luminol only show blood?
Typically, luminol
only shows investigators that there might be blood in an area
, since other substances, including household bleach, can also cause the luminol to glow.
What are some factors that can alter the appearance of a blood stain?
The appearance of a bloodstain can depend on a number of factors, including the velocity at which it was travelling, distance travelled,
the amount of blood, the angle of impact, and the type of target onto which it lands
.
What color is dried blood?
Freshly dried bloodstains are
a glossy reddish-brown in color
. Under the influence of sunlight, the weather or removal attempts, the color eventually disappears and the stain turns gray. The surface on which it is found may also influence the stain’s color.
What shape does blood have in flight?
Experiments with blood have shown that a drop of blood tends to form into
a sphere
in flight rather than the artistic teardrop shape. The formation of the sphere is a result of surface tension and cohesion that binds the molecules together.
Can you tell how old dried blood is?
Non-Destructive Age Testing of Bloodstains
Raman spectroscopy and advanced statistics allow the researchers to date a blood stain accurately, provided said blood stain is
less than two years old
. Raman spectroscopy involves shining a laser on a sample and measuring the intensity of scattered light.
