1. Crime Scene Reconstruction: Bloodstain Pattern Analysis
Lesson 2: General Features of Bloodstain Formation
March 9, 2015
Sanders

2. Bloodstain Formation
Individual bloodstains can convey to the bloodstain analyst the directionality of impact of the blood when it impacted a surface.
Bloodstain Analysis

3. Bloodstain Patterns Bloodstain patterns may convey to the analyst
The location of victims or suspects
The movement of bleeding individuals
Number of blows delivered
Minimum number of blows that struck a bleeding victim
Bloodstain Analysis

4. Information from Pattern Interpretation
The direction from which blood originated.
The angle at which a blood droplet struck a surface.
The location or position of a victim at the time a bloody wound was inflicted.
The approximate location of an individual delivering blows that produced a bloodstain pattern.
Bloodstain Analysis

5. Bloodstain Pattern on the Wall
Bloodstain Analysis

6. Surface Texture
Surface texture is of utmost importance in the interpretation of bloodstain patterns.
When reconstructing the scene, an analyst must use identical surfaces.
Bloodstain Analysis

7. Smooth Surfaces Smooth, nonporous surfaces produce rounder droplets.
Glass
Linoleum
Metal
Marble
Other polished stone surfaces
Bloodstain Analysis

8. Rough Surfaces
Rough or porous surfaces create irregularly shaped bloodstains.
Wood
Plaster
Bloodstain Analysis

9. Satellite Spatter
Small drops of blood that are distributed around the perimeter of a drop of blood and were produced by blood hitting a surface.
Bloodstain Analysis

10. Direction of Travel
The direction of travel of blood striking an object may be determined by the stain’s shape.
The pointed end of the of a bloodstain always faces away from the direction of travel.
Bloodstain Analysis

11. Angle of Impact
The angle of impact is the angle formed between the path of the blood drop and the surface that it contacts.
Bloodstain Analysis

12. Angle of Impact
The angle of impact of an individual bloodstain can be approximated by the degree of distortion or lengthening of the bloodstain.
Bloodstain Analysis