A Probabilistic Assessment of the Complexes of Combined Traces in Secondary Tracks on Fired Bullets
Introduction. The paper analyzes the effectiveness of the application of the method of successively matching traces (CMS method) and the probabilistic method for substantiating the forensic identity of the overlapping secondary traces on fired bullets. Theoretical analysis. The theoretical foundations of the CMS method and the probabilistic method are considered. It is shown that the second method is formed on the basis of two mutually complementary probabilistic models. Experimental studies of the effectiveness of assessing the uniqueness of the complexes of combined tracks. The studies were conducted for secondary traces with high and low track density (for tracks on bullets fired from PM and AK-74, respectively). Potential trace identity criteria were defined for traces with low track density according to the CMS method. The authors determined the probabilistic criteria for the identity of the compared traces with high and low track density. It is shown that for traces with a low track density, the criterion of potential identity is the probability of random alignment of tracks no more than 5*10-3, and for traces with a high density of tracks the probability is no more than 10-6. Results. The probabilistic method allows you to obtain a quantitative assessment of the uniqueness of coincident features and correctly substantiate a categorical positive conclusion when identifying firearms by traces on fired bullets.
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