A method for studying knife tool marks on bone.

Area of Science:

• Forensic Science
• Bioengineering
• Materials Science

Background:

• Knife tool marks on hard tissues provide crucial forensic evidence.
• Understanding the relationship between knife characteristics and bone marks aids investigations.

Purpose of the Study:

• To characterize V-shape tool marks on bone resulting from chopping actions.
• To establish a correlation between knife angle, bone elasticity, and mark characteristics.

Main Methods:

• A custom chopping stage with a gravity accelerator was used to simulate knife impacts on pig bone.
• A digital microscope measured the knife angle (θ) and the resulting V-shape tool mark angle (ψ).
• The elasticity coefficient (κ = θ/ψ) was calculated and correlated with impulsive force.

Main Results:

• A consistent correlation was found between the V-shape tool mark angle (ψ) and the elasticity coefficient (κ) under constant impulsive force.
• The study quantified the relationship between the knife's physical attributes and the resulting bone tissue damage.

Conclusions:

• The derived elasticity coefficient (κ) is a valuable metric for analyzing knife marks on bone.
• These findings enhance the medicolegal investigation of sharp force trauma involving knives.