A part-declared blind testing program in firearms examination. Issue 4 (July 2018)

• Record Type: Journal Article
• Authors: Kerkhoff, W.; Stoel, R.D.; Mattijssen, E.J.A.T.; Berger, C.E.H.; Didden, F.W.; Kerstholt, J.H.
• Is Part Of: Science & justice. Volume 58:Issue 4(2018)
• Page Start: 258
• Page End: 263
• Publication Date: 2018-07
• Subjects: Part declared testing -- Blind testing -- Fake cases -- Bullet and cartridge case comparison -- Proficiency test; Forensic sciences -- Periodicals; Criminal investigation -- Periodicals; Forensic Medicine -- Periodicals; Jurisprudence -- Periodicals; Criminalistique -- Périodiques; Enquêtes criminelles -- Périodiques; Criminal investigation; Forensic sciences; Electronic journals; Periodicals; 363.2505
• DOI: 10.1016/j.scijus.2018.03.006
• Languages: English
• ISSNs: 1355-0306

Abstract

Abstract: In 2015 and 2016 the Central Unit of the Dutch National Police created and submitted 21 cartridge case comparison tests as real cases to the Netherlands Forensic Institute (NFI), under supervision of the University of Twente (UT). A total of 53 conclusions were drawn in these 21 tests. For 31 conclusions the underlying ground truth was "positive", in the sense that it addressed a cluster of cartridge cases that was fired from the same firearm. For 22 conclusions the ground truth was "negative", in the sense that the cartridge cases were fired from different firearms. In none of the conclusions, resulting from examinations under casework conditions, misleading evidence was reported. All conclusions supported the hypothesis reflecting the ground truth. This article discusses the design and results of the tests in more detail. Highlights: The performance of the Netherlands Forensic Institute's (NFI) Firearms Section was tested in a part-declared validity study. The 21 tests were prepared by external parties and submitted as real forensic cases to the NFI. In 18 tests the examiners could not distinguish the tests from real cases. All 50 conclusions supported the hypothesis reflecting the ground truths of the 21 tests.