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Crimelab - Bloodstain Analysis

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LAB REPORT

BLOODSTAIN ANALYSIS

(http://www.crimescene-forensics.com/images/Blood_Spatter_001B.gif)

COURSE: CHM 1107: Introduction to Forensic Science - Professor Ira S. Krull

DATE: 10.27.11

INTRODUCTION

Blood is a biological fluid found in animals that delivers necessary nutrients and oxygen throughout the body and carries away metabolic waste products. The average adult has a blood volume of roughly 5 liters, comprising of plasma, blood cells and platelets, and it is usually red in color, though not always. The most abundant cells in vertebrate blood are red blood cells, constituting about 45% of whole blood. These cells contain hemoglobin, an iron-containing protein, which distributes oxygen throughout the human body.

Blood is circulated around the body through blood vessels by the pumping action of the heart. In humans, blood is pumped from the strong left ventricle of the heart through arteries to peripheral tissues and returns to the right atrium of the heart through the superior vena cava (see Fig 1). It then enters the right ventricle and is pumped through the pulmonary artery to the lungs and returns to the left atrium through the pulmonary veins. Blood then enters the left ventricle to be circulated again.

(Fig 1: http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Diagram_of_the_human_heart_%28cropped%29.svg/220px-Diagram_of_the_human_heart_%28cropped%29.svg.png)

Blood is a type of evidence found most often at violent crime scenes and submitted to forensic laboratories for further identification and analysis. The investigators at the crime scene always seek to answer three questions when in contact with bloodstains: (1) Is this blood? (2) Is it from a human? (3) How closely does it match the blood of the victim or suspect? Answers to these questions can be found through several analyses and tests carried out by the forensic

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