Serology - Blood Spatter Analysis
Goal: Determine the sequence of events and the approximate position of the victim when blood exited the body
Understand the laws of physics concerning liquids such as surface
tension and cohesive force.
Measurement tools (rulers, measuring tape, protractor, etc)
CAD software or BackTrack™
This is the general procedure for blood spatter analysis. Please follow any specific procedures that might have come with your ordered kits.
1. Instructor must go over “Safety Biohazard” in case the instructor has not done it in the previous activity.
2. The teacher reviews theories and background information: mathematical and physical concepts in blood spatter analysis.
3. Instructor must enforce the students to wear safety equipments before they touch any instruments and evidence, especially blood spatter samples.
4. First, students will distinguish if stains are blood. Then, they may perform serology as optional experiment if time permits. Confirm if the spatter is from the victim’s blood.
5. Students will determine what the position and shape of the blood spatter indicates.
6. Students will investigate the relationship between the height that blood was dropped from and the diameter of the blood drop on impact.
7. Students will analyze the surface where bloodstain is present. By then, students should have some knowledge about the relationship between blood spatter type and surface texture.
8. Student will design a visual model with blood flight path data they have collected. The visual model can be made either with CAD software or old conventional way by using strings.
Analysis and Conclusion
State several reasons why wet blood would be more valuable than dried blood in a crime scene.
2-3 class period for theory and background