Problems of Forensic Sciences 2015 Vol. 102 (CII) 115-137
GLASS FRAGMENTS AS IMPORTANT CRIMINALISTIC EVIDENCE – CASE STUDIES
Aleksandra MICHALSKA, Grzegorz ZADORA, Maciej ŚWIĘTEK
Institute of Forensic Research, Kraków, Poland
Streszczenie
Herein the authors present examples of real forensic cases in which glass fragments constituted important evidence. Both large glass objects and glass microtraces were examined. In the case of large glass objects, tool marks examinations (mostly “jigsaw fit” analyses) were performed, while in the case of glass microtraces (and large glass fragments for which tool mark examination was insufficient), elemental composition was determined using a scanning electron microscope coupled with an energy dispersive X-ray spectrometer. In most cases, data obtained from physicochemical analyses (cases II−IV) were additionally interpreted with the use of the likelihood ratio test. Glass evidences were analysed in order to establish: if car lights were switched on during a collision (case I); if a car was involved in a hit-and-run accident (case II); if a pneumatic gun was used for breaking into a car (case III); and whether an event was an accident or not (case IV). Most of the presented cases could only be solved because combined information obtained from tool marks examinations and physicochemical analyses of glass supported by the likelihood ratio approach were used.
Słowa kluczowe
Glass fragments; Tool marks examination; Elemental content of glass samples; SEM-EDX; Likelihood ratio.