Problems of Forensic Sciences 2001 Vol. 47 (XLVII) 363-367
FORENSIC USE OF PHILIPS XL 30 ESEM
Vojin MASTRUKO
Forensic Centre of Ministry of Interior, Zagreb, Croatia
Streszczenie
Since late 1998, SEM has been installed in Forensic Centre, Zagreb, Croatia. Philips’ Environmental Scanning Electron Microscope (ESEM) XL 30 with EDAX EDX-detector and Philips’ GSR NT v. 3.2 software is dedicated primarily for investigation of gunshot residue particles (GSR). Instrument spectral resolution is about 142 eV at amplification time of 10 microseconds which qualifies the instrument to be one of the best tools for GSR analysis. At the moment we are still performing laboratory testing involving typical number of three-component and two-component particles on the back of a shooter hand immediately after shooting. Because of a rapid loss of GSR particles with time elapsed after shooting, we have doubts about taping the hands only. It seems that taping hand only is adequate just for suicide cases. On the other hand taping hair, moustaches and beard didn’t appear to be of much help because of big spread in results. Our last results showed that perhaps it would be a good idea to combine two different sampling and analytical methods (GSR and modified Gonzales test). Another field of application of ESEM is as a comparative microscope. Acording to our specifications Philips made a special ballistic stage that can accept two cases (shells) or bullets. By use of Philips’ software “Picture in Picture” we managed to use single SEMas a comparative electron microscope. Manual matching works wery well and it is reasonable in cases of matching of very small mechanical traces (typically toolmarks on wires) or in cases of traces on curved surfaces (typically strong deformed bullets).
Słowa kluczowe
SEM; GSR.