Development of an objective method for the comparison of fired projectiles using an air pistol as a template

Noor Hazfalinda Hamzah

Research output: Contribution to journalArticle

3 Citations (Scopus)
18 Downloads (Pure)

Abstract

The ability to objectify ballistic evidence is a challenge faced by firearms examiners around the world. A number of researchers are trying to improve bullet-identification systems to address deficiencies detailed within the National Academy of Science report (2009). More recently focus has turned to making use of more sophisticated imaging modalities to view entire regions of the projectile and the development of automated systems for the comparison of the topographical surfaces recorded. Projectiles from a newly bought air pistol with 0.177 calibre pellets (unjacketed), fired series of 609 pellets were examined using an optical microscope. A mathematical methodology was developed to pre-process the resultant topographical maps generating point data for comparison, analysed using the principal component analysis (PCA). In most cases limited to reasonable success was achieved. The objective method still requires an operator to identify the Land Engraved Areas to be scanned, however the mathematical alignments were objectively achieved. The PCA results illustrated that the striation marks were neither exclusive nor specific to the LEA regions but rather crossed over regions. This study also proves that a single weapon does not necessarily leave identical marks of projectiles on its surface.

Original languageEnglish
Pages (from-to)106-112
Number of pages7
JournalForensic Science International
Volume264
Early online date13 Apr 2016
DOIs
Publication statusPublished - 1 Jul 2016
Event7th European Academy of Forensic Science - Prague, Czech Republic
Duration: 6 Sep 201511 Sep 2015

Keywords

  • acquired characteristics
  • air weapon and pellets
  • bullet-identification system
  • principal component analysis
  • surface topography measurements
  • unjacketed bullets

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