Blood Stain Analysis
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Outline
1. Introduction
2. Blood Analysis History
3. Blood at a Crime Scene
a. Tools
b. Techniques
4. Blood analysis applied
a. Cases
b. Evidence
5. How it has changed CSI
6. Conclusion
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Abstract
The purpose of this research document is to examine the history, process, applied
science, and how it has changed crime scene investigation. The history of blood analysis will be
examined to see where it started and where it is now. The process will be shown and the
techniques explained as well as the tools shown. More examination will take place on the
application of these processes and how they have been used in real world cases. Finally a look at
what it has done to change crime scene investigation for the better.
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Blood stain analysis is a crucial part of crime scene investigation. Blood can be found at
many crime scenes and it is one of the most helpful pieces of evidence when trying to solve a
case. The blood tells a story, it can show a crime scene investigator where a person has been,
what kind of weapon was used, where the crime took place, if the crime scene was tampered
with, even how the crime took place. A good blood stain examiner can find all this and more
from smears, streaks, pools and drops of blood. Blood Stain Analysis is one of if not the most
important crime scene investigation tool because it can paint such a clear picture of what
happened at a crime scene. Blood splatter is a crucial tool in investigation and has been around
for over a hundred years but few knew the wide scale benefits it could have until recently.
Blood stain analysis has been around a long time; in fact research shows that it has been
studied all the way back to the 1890’s. However it was not widely accepted and the benefits were
not clear to those who could help promote it. Even though blood stain analysis had its beginning
in the 19th century the first ground breaking case did not take place until 1955 in The State of
Ohio v. Samuel Sheppard. Dr. Paul Kirk entered an affidavit that showed the position of the
assailant and the victim as well as which hand was used to strike the victim, this case marks the
first time the legal system recognized the importance of blood analysis. (Freeman) Two books
have been written that have shaped the past present and future knowledge of blood splatter
analysis one is titled Concerning the Origin, Shape, Direction and Distribution of the Bloodstains
Following Head Wounds Caused by Blows. By Eduard Piotrowski this ground breaking title
offered interpretation of blood that was not scene until half a century later. The other is Flight
Characteristics of Human Blood and Stain Patterns written in 1971 by Dr. Herbert MacDonnel.
He was also one of the first to start training law enforcement in blood and was a founder of the
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International Association of Blood Pattern Analysis. (Freeman) I believe to know anything
about a current topic we must examine its past. To know the history of a topic can give us great
insight into what we are now doing in the field. Blood analysis has been around a long time and
comes from humble beginning but now it is one of the most important investigation techniques at
a crime scene.
The crime scene is the place where the crime was acted out, it can be anywhere and
involve anything, but most of the time it involves blood. Blood is so important because when it
has been studied correctly it can tell a great many things about a crime scene; for instance who
was involved and where they were positioned, how the attack took place a struggle or one sided,
and determine if there is validity in witness accounts. (Blood) Blood has many different
characteristics because it is a liquid this is called blood flight characteristics. The current way
blood is classified is based on the physical features of the blood stain size, location, and
distribution. These features break down into three categories passive, spatter, and altered.
(Gardner) All three are important because they ultimately tell a story, the story of the crime and
how it took place. Passive stains are affected by gravity and contact with the blood, gravity can
mean droplets or flow of blood. Contact encompasses all transfer patterns from surface to
surface. (Gardner) Why are these important? Think about a crime scene if a person is sitting in a
chair after suffering a blow to the head blood will drip down off of them creating small pools of
blood all around. Once again this can show a blood pattern examiner exactly where the person
was, if they were moved, even how long they have been there depending on how big the pools
are and if they are dry or not. Size of droplets determines how far they are falling from, the
bigger the drop the further away the blood is falling again this can show if a body or the victim
was moved and in some cases blood droplets can even be used to find the location of a body.
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Another example is if a person has been wounded and fallen to the floor blood will slowly flow
from the wound. The size of the flow, direction of it, and viscosity of the blood can tell an
examiner much about the scene. Gravity plays an important part in the analysis because gravity
is constant blood is expected to behave in a certain way, when it does not an examiner has a huge
clue that someone has tampered with or moved something to cause the contradiction of gravity.
Prints left in pools of blood are lifted to obtain shoe prints which are another valuable item when
trying to solve a criminal case. Motion transfer patterns are a great help at a crime scene because
what they do is indicate movement. Movement at a crime scene can help investigators have a
better understanding of what happened. These movements can detail the path of the suspect or
victim also any attempts to clean the crime scene which will lead police to the knowledge that
someone is trying to cover it up. (Gardner) These transfer patterns are usually wipes from
extremities, hair and clothing moving through blood and depositing it in another position. This is
such valuable knowledge because of the fat that it shows how people moved and interacted
before the police showed up at the scene which can lead to astounding clues in a criminal
investigation.
These are just a small sampling of why blood spatter analysis is as important as stated
before they can show a clearer picture of what took place at a crime scene than almost all other
evidence.
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Works Cited
"Blood Stains." Blood Stains. Web. 19 Sept. 2012. <http://www.crimesceneforensics.com/Blood_Stains.html>. This website shows and describes the different ways
blood will appear at a crime scene and how to identify what has taken place
"Forensic Magazine." Forensic Magazine. Web. 19 Sept. 2012.
<http://www.forensicmag.com/>. This magazine has many articles on crime scene
procedure and what takes place including blood analysis.
Freeman, Shanna. "How Bloodstain Pattern Analysis Works." HowStuffWorks. Web. 19 Sept.
2012. <http://science.howstuffworks.com/bloodstain-pattern-analysis4.htm>. This
describes all the steps of blood analysis as well as information on the history of the
subject. Also it shows real life applied blood analysis in the field.
Gardner, J. (2012, October 23). Lecture Presentation on Blood Stain, CRM 3997 001 Crime
Scene Investigation. Ordway 121 Florida Southern College.
"International Association of Bloodstain Pattern Analysts | IABPA." International Association of
Bloodstain Pattern Analysts | IABPA. 2011. Web. 19 Sept. 2012.
<http://www.iabpa.org/>. This is the chief website for blood pattern analysts. It has
documents on the subject as well as updated news and real time information.