The Accuracy and Repeatability of Reconstructing Single Bullet Impacts Using the 2D Ellipse Method.

Area of Science:

• Forensic Science
• Ballistics
• Crime Scene Reconstruction

Background:

• Bullet impacts on surfaces provide crucial data for trajectory analysis.
• The ellipse method is a technique used to estimate bullet impact angles.
• Accurate reconstruction of shooting scenes relies on precise impact analysis.

Purpose of the Study:

• To evaluate the accuracy and repeatability of the ellipse method for determining single bullet impact angles.
• To identify optimal ammunition calibers and angles of incidence for reliable crime scene reconstruction.
• To assess the effectiveness of the ellipse method in forensic ballistics.

Main Methods:

• Live-fire testing of four ammunition calibers into drywall panels at 11 varying angles of incidence (88° to ricochet).
• Recording 5 shots per caliber per angle (n=220 total impacts).
• 31 participants estimated impact angles using the ellipse method.

Main Results:

• The 0.45 caliber ammunition demonstrated the highest accuracy and repeatability.
• Lower angles of incidence (<64°) consistently improved performance across all calibers.
• The ellipse method proved useful for most single bullet impact analyses in drywall.

Conclusions:

• The ellipse method is a valuable tool for crime scene reconstruction, particularly for single bullet impacts in drywall.
• Ammunition caliber and angle of incidence significantly influence the accuracy of the ellipse method.
• Further research may refine the application of the ellipse method based on specific firearm and ammunition characteristics.