Chapter 8 Blood and Blood Spatter Explain the

Chapter 8 Blood and Blood Spatter • Explain the composition of blood • Describe the function of blood cells • Determine the blood type of a blood sample • Conduct a blood spatter analysis • Examine wounds and describe the nature of the weapon • Find and process blood evidence Forensic Science: Fundamentals & Investigations, Chapter 8 By the end of this chapter you will be able to: 1 All Rights Reserved South-Western / Cengage Learning © 2012, 2009

Introduction and History Forensic Science: Fundamentals & Investigations, Chapter 8 • Blood typing provides class evidence 2

Introduction and History Forensic Science: Fundamentals & Investigations, Chapter 8 • DNA profiling provides individual evidence 3

• A blood spattern provides information • the truthfulness of an account by a witness or a suspect • the origin of the blood • the angle and velocity of impact • the type of weapon used Forensic Science: Fundamentals & Investigations, Chapter 8 Introduction and History 4

Forensic Science: Fundamentals & Investigations, Chapter 8 Composition of Blood 5

Forensic Science: Fundamentals & Investigations, Chapter 8 Composition of Blood 6

Composition of Blood Forensic Science: Fundamentals & Investigations, Chapter 8 • Plasma—a liquid suspending other blood components 7

Composition of Blood Forensic Science: Fundamentals & Investigations, Chapter 8 • Red blood cells (Erthrocytes)—carries oxygen to the body’s cells and carbon dioxide away 8

Composition of Blood Forensic Science: Fundamentals & Investigations, Chapter 8 • White blood cells (Leukocytes)—fights disease and foreign invaders and, alone, contain cell nuclei 9

Composition of Blood Forensic Science: Fundamentals & Investigations, Chapter 8 • Platelets—aids in blood clotting and the repair of damaged blood vessels 10

Composition of Blood Forensic Science: Fundamentals & Investigations, Chapter 8 Can you identify the different blood cells? 11

Forensic Science: Fundamentals & Investigations, Chapter 8 Types of Blood Cells 12

Forensic Science: Fundamentals & Investigations, Chapter 8 Cellular Components of Blood 13

Blood Typing—Proteins Forensic Science: Fundamentals & Investigations, Chapter 8 • Discovered in 1900 by Karl Landsteiner 14

42% 12% 3% of the population in the United States 43% Forensic Science: Fundamentals & Investigations, Chapter 8 Blood Typing—Proteins 15

Rh System • 1940, Alexander Weiner found a protein common to his rhesus monkeys and to some humans. It was called the Rh protein.

Forensic Science: Fundamentals & Investigations, Chapter 8 Blood compatibility 18