READ: Components of Blood

Introduction

 When a stain is found at the scene of a crime, the first thing that has to be determined is whether the stain is blood. Forensic serology is the science that deals with blood and body fluids to determine if it is human and if it can be traced to a particular source. In addition to serological testing, blood spatter analysis can provide valuable information to help reconstruct the events at a crime scene to support or refute statements made by the suspect, the victim, or witnesses.

Essential Questions

1. In what ways does serological evidence help solve a crime?

2. What type of information can be determined from a drop of blood?

3. How is blood typing done?

4. What information can we get from blood stain patterns?

5. How is blood analyzed in the Forensic lab?

6. How is paternity established through blood testing?

Module Minute

Serology involves the properties and reactions of serums, especially blood serum. Often in a crime scene, blood and other body fluids are present and can be tested to identify a suspect or victim if either is unknown. The secrets of the body are written in the blood; a single drop of blood contains red blood cells, white blood cells, platelets and plasma. From the white blood cells, DNA can be extracted and eventually analyzed if enough is present in the sample. Blood stain patterns at a crime scene can help sometimes yield important clues such as the type and velocity of the weapon, the number of blows, the handedness of assailant, position and movements of the victim, order of inflicted wounds, types of injuries, estimation of when crime was committed, and whether the death was immediate or delayed.

Georgia Virtual, Forensic Serology, CC BY-NC-SA 3.0