A part-declared blind testing program in firearms examination
W Kerkhoff1, R D Stoel1, E J A T Mattijssen2
1Netherlands Forensic Institute, PO Box 24044, 2490 AA The Hague, The Netherlands.
Summary
Forensic firearm analysis by the Dutch National Police demonstrated high accuracy. Cartridge case comparisons under real casework conditions yielded no misleading evidence, with all conclusions aligning with ground truth.
Area of Science:
- Forensic Science
- Ballistics
- Firearm Examination
Background:
- The Central Unit of the Dutch National Police conducted cartridge case comparison tests.
- These tests were performed under real casework conditions between 2015 and 2016.
- The Netherlands Forensic Institute (NFI) and the University of Twente (UT) supervised the study.
Purpose of the Study:
- To evaluate the accuracy and reliability of firearm forensic analysis.
- To assess the outcomes of cartridge case comparisons conducted under operational conditions.
Main Methods:
- 21 cartridge case comparison tests were submitted as real cases.
- A total of 53 conclusions were drawn from these tests.
- Ground truth was established for each conclusion, indicating whether cases were fired from the same or different firearms.
Main Results:
- 31 conclusions had a 'positive' ground truth (cases from the same firearm).
- 22 conclusions had a 'negative' ground truth (cases from different firearms).
- No misleading evidence was reported in any of the 53 conclusions.
Conclusions:
- All conclusions drawn from the cartridge case comparisons supported the ground truth.
- The study indicates high reliability in forensic firearm examination under real casework conditions.
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