it is about blood stain pattern analysis from a crime scene.

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By,
Gopika Babu
1st
Year MSc. Forensic
science Lovely
Professional University

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As we all know Blood Stain Pattern found in the crime scene
plays an important role in the crime investigation as well as crime
reconstruction. It was found on 1895. Dr. Eduard Piotrowski is known to
be the scientist who developed method for analyzing blood stain pattern.
It is important to analysis the blood stain pattern found from the crime
scene. Blood stain pattern analysis means the shapes, locations,
distribution of patterns of bloodstains are analyzed, in order to provide an
interpretation of physical events that gave rise to their origin. It uses the
principles of the biology, physics and mathematics.
By using blood stain pattern analysis, analyst will not
only determine what could happened, also can determine what could not
be happened. Blood stain pattern analysis plays an important role in the
forensic significance of the blood.

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Before going to details about the blood stain pattern
analysis, its important to know why blood stain pattern is analyzed. For
that its important to know what’s blood and why its important in crime
scene and what its forensic importance.
Blood is a liquid connective tissue which helps in
transportation of the respiratory gases and removal of metabolic wastes
from body. As we know there are different components in blood, each
component has different functions.
From the blood found from crime scene, by using physics
and mathematics methods the origin and force applied to produce that
blood spatter can be calculated. By calculating that, what could and could
not be happened in that crime scene can be analyzed.
Other importance is, it is important to know whether the blood found
from the crime scene is human origin or not. It can be done by chemical
tests like Kastle-Meyer test, precipitin test etc. If it is found human origin,

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next is to determine the donor of the blood spatter found in crime scene.
It can be done by DNA analysis. Then by the decomposing activity of the
blood it is possible to determine the time of death.
Blood stain pattern are mainly of three types:
 Passive Blood Stains
It is created from force of gravity.
Example – drops, series of drops,
flow patterns, blood pools etc.
 Projected Blood Stains
It is created when the force is
applied to the source of the
blood.
Example – spatters, cast off stain,
Arterial spurting etc.
 Transfer Blood Stains
It is created when wet or bloody
object comes in contact with
the target surfaces. These are of
Two types: wipe pattern & swipe
Pattern.
Other types of blood stain patterns are:
 Cast off stains
 Shadowing and Ghosting
Blood Stain Pattern

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 Swipes and Wipes
Blood stain pattern analysis is the interpretation of
blood stain from the crime scene to recreate the action that can be
happened there. Here, analysts will examine the size, shape, distribution
and location of the blood stains found in the crime scene.
By performing these analyze, it will be answer to different questions:
 From where the blood comes?
 What can be the cause of wounds?
 From what direction the wounds can be caused?
 In what position did victim and culprit can be?
 How many culprits can be there?
The primary step in blood stain pattern analysis is to determine the
difference between the spatter and transfer.
Spatter: - It is produced when the source of blood is acted upon by external
force. This blood droplet travels through the air before it reaches the target
surface.
Transfer: - It is produced when the blood source comes in direct contact
with the target surface.
Analysis of Blood Stain Pattern

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The importance of analyzing the blood spatter analysis is because the
greater amount of the force applied to the source of the blood will produce
lesser amount of blood spatter. Another thing is if spatter is found on
suspected person’s cloth or body, it indicates that at time of the force was
applied the suspect was in direct to the source of blood spatter.
The blood drop usually falls from the source usually forms in
the spherical form. This is due to surface tension.
Surface which the blood drop falls also affects the pattern. If the stain falls
on the smooth surface it will make smooth, circular and smooth-edged
blood stain. If the stain falls on hard surface it will make irregular, rough
edged blood stain.
In gunshot cases also there is importance of blood stain pattern analysis.
Because in gunshot cases, it will be 2 types of spatter; Forward spatter and
Backward spatter. By analyzing the spatter, we can determine the size or
caliber of the bullet also the distance from the muzzle end of gun to target.
 Blood spatter analysis can be done by following methods:
 Finding the directionality of the blood stain
It indicates the path of the droplet followed at the time it impacts
on target.
 Impact angle determination

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Acute angle formed between the direction of blood drop and the
surface it strikes.
Sin = width/length of the droplet
 Point of convergence
It indicates the intersection of two bloodstain pathways. Using
this directionality of more than one blood stain can be
determined.
 Point of origin
It indicates the origin from which the blood stain can be
originated.
 From this we can conclude that Bloodstain pattern analysis is used to
determine how bloodstain arise from the source of the blood. This
blood spatter analysis can be used for any purposes in the crime
investigation.
Bibliography
 http://www.crimescene-forensics.com/BSPA.html

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 http://www.forensicsciencesimplified.org/blood/
 https://www.bmi.gv.at/104/Wissenschaft_und_Forschung/SIAK-
Journal/internationalEdition/files/Brodbeck_IE_2012.pdf