1. Crime Scene Reconstruction: Bloodstain Pattern Analysis
Lesson 3: Impact Bloodstain Spatter Patterns
March 9, 2015
Sanders

2. Forward Spatter Forward Spatter: Back Spatter:
Blood that travels away from the source in the same direction as the force that caused the spatter.
Back Spatter:
Blood directed back toward the source of the force that caused the spatter.
November 30, 2018
Bloodstain Analysis

3. Spatter Patterns
November 30, 2018
Bloodstain Analysis

4. Low Velocity Spatter
An impact spatter pattern created by a force traveling at less than 5 feet per second or less.
Produces drops with diameters greater than 3 millimeters.
November 30, 2018
Bloodstain Analysis

5. Medium Velocity Channel
An impact pattern created by a force traveling at 5 to 25 feet per second.
Produces drops between 1 and 3 millimeters.
November 30, 2018
Bloodstain Analysis

6. High Velocity Spatter
An impact spatter pattern created by a force traveling at 100 feet per second.
Produces drops with a diameter of less than 1 millimeter.
November 30, 2018
Bloodstain Analysis

7. Area of Convergence
The area of convergence is the point on a two-dimensional plane from which the drops of an impact spatter pattern originated.
November 30, 2018
Bloodstain Analysis

8. Convergence
This area can be estimated by drawing straight lines through the long axis of several individual blood stains, following the line of their tails.
November 30, 2018
Bloodstain Analysis

9. Causes of Spatter
November 30, 2018
Bloodstain Analysis

10. Area of Origin
The area of origin of a bloodstain pattern is the area in three-dimensional space where blood was projected from, showing the position of the victim or suspect when the event took place.
November 30, 2018
Bloodstain Analysis

11. Area of Origin
The string method is commonly used at a crime scene to approximate the position of the area of origin.
November 30, 2018
Bloodstain Analysis

12. Area of Origin
November 30, 2018
Bloodstain Analysis