Transcript Blood Splatter Patterns

Original presentation by
Detective Gregory Restina
Mrs. Patricia Nolan Bertino .03
Modified by
Anthony Bertino .04
Marna Chamberlain 2010
With materials from Collins, Osselman and Turner
Bloodstains are one of
the most common
types of physical
evidence found at a
crime scene.
Why study Blood Spatter?
◊ To find out where an assault occurred
◊ To find out the position of the killer during the attack
◊ To find out if the victim was walking or running
during the attack
◊ To find out if victims tried to avoid the blows, by
holding up object or arms to avoid the hits.
(There would be a gap in the spatter if this happened.)
◊ To find out the type of blood for victim or suspect
identification
◊ To find out how long the blood has been there
to find a time frame for the attacks
Surfaces
If the surface is more
rough and porous, the
spatter will be absorbed.
This picture shows the
blood spatter on a carpet.
If the surface is hard,
smooth and flat, like tile,
the spatter will break up
into lots of little drops, and
they will be round. This
picture shows a close up
of one of the drops.
The greater the height,
the greater the amount
of spatter.
From close range, the
droplets of spatter are
closer together. A low
velocity impact, like a blow
from a hammer, will also
produce this type of
spatter.
From further away, the range of
the spatter is more spread out.
The darkened edges of the hole
show that a bullet was fired to
cause the spatter. This is a high
velocity impact.
There are many
different patterns
that are created
when blood is
spilled. Most of
these patterns have
special names.
Arterial Spurting (or
Gushing) Pattern Bloodstain pattern that
results from blood exiting
the body under pressure
from a breached artery. The
blood gushes out with the
rhythm of the heart.
Cast off pattern- Created when
blood is released or thrown from
a blood bearing object in motion
(for example a knife). These are
also called cast-off stains.
Drip Pattern- A blood
stain pattern which
results from dripped
blood either from a
weapon, victim or
sometimes the killer.
Flow pattern- A
blood stain pattern
which shows a
change in shape
and direction due to
gravity or other
forces.
Types of Blood Spatter
• Passive
dripped blood
• Transferred hand print
• Projected artery bleed
• Cast off
from a weapon
Transferred blood
Footprint
Handprint
Projected blood
Arterial gush on wall
Patterns of transfer
ceiling
Cast-off from Weapon
Swipe pattern- this
pattern is created when
blood is transferred from
a moving source onto
an unstained surface.
Contact PatternsThese types of
patterns occur
when a wet or
bloody surface
comes into
contact with a
second surface.
This type of stain can tell
how many times a person
was hit. The number of
stains is always one less
than the number of hits,
because the first time the
weapon hits there is no
blood on it.
Blood Detection
• Phenolphthalein
• Luminol
Luminol is a chemical that
reacts with the hemoglobin
in the blood to produce a
blue luminescence.
Luminol is used by
investigators when the
blood is wiped away and
is therefore no longer
visible to the naked eye.
The brighter and stronger the glow, the
more recent (and fresh) the blood is.
The brighter and stronger the glow,
the more heavy the blood flow.
Arterial Gush
Passive
Transfer
Projected
Low Velocity Impact
Medium Velocity Impact
High Velocity Impact
High Impact
90 degrees
Over Hand Swing
Left to Right
Crime Scene Diagrams
& Photos