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Summary of the Examination Method

The following is a brief summary of the methodology typically used for the comparison of toolmarks which can be summarized by the acronym "ECCCV".  ECCCV stands for Evaluation, Classification, Comparison, Conclusion, and Verification.  Further detail can be found in sources such as the OSAC Standard "OSAC 2024-S-0002 Standard Test Method for the Examination and Comparison of Toolmarks for Source Attribution", the AFTE/OSAC process map, and individual laboratory procedures.  

Evaluation

The assessment of a specimen for features to determine its suitability for further classification and/or comparison.

Classification

The determination of a specimen’s discernible class characteristics, thereby defining the class to which it belongs (e.g., a .45 caliber bullet bearing five groove impressions and right twist).

Comparison

The side-by-side examination of two toolmarks. This comparison may be performed microscopically or macroscopically, as needed.

Conclusion

Opinion stated by an examiner after interpretation of data observed when comparing toolmarks.

Verification

An independent comparison or analysis of items previously examined by the primary examiner to provide a quality check of value determinations or source conclusions.