3 Types Of Blood Stains

Crime Scene Forensics, LLC

Examining and Documenting

Blood Stain Patterns

Bloodstain Design Assay: is the examination of the shapes,

locations, and distribution of patterns of bloodstains, in social club to provide

an estimation of the physical events that gave rising to their origin.

The following Data may be obtained from a

proper Bloodstain Blueprint Analysis:

1. Distance from the claret source to the target

2. Direction of travel and impact angles

three. Nature of the strength used to cause the mortality

four. The object used to cause the bloodshed

5. Sequencing of multiple bloodshed events

half-dozen.Interpretation of contact or transfer patterns

When properly documented, bloodstain patterns found at the crime scene, or on a particular person's clothing, can be used to:

1. Ostend or abnegate the position of a victim, witness, doubtable, or defendant

2. Determine if at that place is evidence of a struggle, or if the assail is "one sided"

3. Confirm or refute statements fabricated by principles in the instance:

IE: Are stain patterns on a particular person's vesture consistent

with accounts given by the victim, witness, or accused?

Blood Flight Characteristics:

Claret will not suspension up unless it is acted upon past force. The force must be not bad enough to overcome the surface tension of the blood

Claret forms a spherical shape (perfect circular shape) almost immediately upon separating from the claret source. The spherical shape is acquired by the surface tension of the claret.

Surface Tension causes the blood drop to pull itself in; both horizontally and vertically.

The blood driblet will settle into a spherical shape, as a result of the surface tension.

The surface tension will maintain the sphere shape of the blood driblet until it impacts with the

surface.

SPATTER VS TRANSFER: The simplest type of blood spatter analysis is determining spatters from transfers.

Spatters are created when blood is acted upon by strength, and travels through the air before landing on a

target surface.

Transfers occur when a claret source comes in direct contact with a target surface area.

TARGET SURFACE TEXTURE:

• Bloodstains tin occur on a variety of surfaces. The type of
surface that gratuitous falling blood strikes affects the
appearance of the resulting spatter.
• Blood drops on a smooth surface will make a more uniform
or regular circular shape.
• Claret drops on a rough surface will make an irregular
shaped stain with rough or jagged edges.

Low FORCE (VELOCITY) Impact SPATTER/PASSIVE DROPS:

• Blood that falls at the speed or force of normal gravity

• These spatters usually fall from an open up wound, or from a
surface that is saturated with blood

• The majority of the Low Force Impact Spatters are large,
circular, spatters with diameters of 4mm or more

• Low Forcefulness Impact Spatters will increase in size as the
distance fallen increases, nevertheless, the size of the spatters
will remain abiding after approx 4 feet

MEDIUM Forcefulness (VELOCITY) Bear on SPATTER:

• Produced with more than energy or force than gravity

• The forcefulness of the impact causes the blood to break into
smaller size spatters relative to the amount of force applied

• This type of spatter is usually seen in blunt forcefulness, stabbings,
and secondary spatters

• Produced when the majority of larger drops of blood are
broken into smaller spatters with diameters of 2 – 4 mm

• The force associated with this type of spatter is greater than
25 ft per 2d

Loftier Forcefulness (VELOCITY) IMPACT SPATTER:

• Touch on spatter that measures less than 2mm in
diameter
• The force necessary to produce this size spatter
is greater than 100 ft per second
• This blazon of spatter is ordinarily associated with
gunshots, explosions, and high speed collisions
• High Force Impact Spatter takes on a "mist similar"
appearance

IMPACT SPATTERS: are a random blueprint of spatter of varying sizes

It is of import to notation that the term "Velocity" does non measure the speed at which the blood is traveling, but rather is used to draw or measure out amount of force practical to the claret, to cause it to spatter.

Bending of Impact:

The steeper the impact, the more

elliptical or elongated, the claret drop

Direction:

The "tail" points to the direction of

the claret drib

Angle of Bear on

• Measure the width and the length of the stain/spatter

sine= width = 9mm

length = 18mm

• ix divided by eighteen = 0.500
• Arcsine 0.500 = xxx degree bending of affect

• Do not measure the "tail"

• it is a secondary force or event.

• Dissever the smaller number past the larger number

Back SPATTER OR "BLOWBACK"

• When a bullet strikes a target, some loftier forcefulness touch on spatter may exist directed back toward the gun that fired the shot. This is known every bit "back spatter"

• If the bullet exits its target, a larger
amount of high strength affect spatter may exist directed in the aforementioned direction equally the bullet. This is known as "forward spatter".

The amount of high force bear on spatter created volition depend upon the size or caliber of the bullet fired, too equally the distance from the gun to the target. The larger the bullet, or projectile, the greater

the spatter. The closer to the target that the gun is fired...the not bad the spatter.

For a complete listing of bloodstain blueprint terms, as recommended by the Internation Clan of Claret Stain Pattern Analysts. (IABPA), become to: http://www.iabpa.org/ These terms should serve as a guide, for those who piece of work and teach in the field of Blood Stain Pattern Analysis. These terms are not meant to exist all encompassing

To cite this website: Crime Scene Forensics, LLC, New York; www.crimescene-forensics.com