Based upon the recently developed glue-lift collection of gunshot residue particles for examination in the scanning electron microscope with energy dispersive X-rays, this laboratory has undertaken a research program to determine if reconstruction of gunshot deaths is feasible. Because undisturbed conditions of suicide victims may help in securing unambiguous results and high success rates, the program has been carried out to reconstruct suicides only. Data obtained from 13 firearms suicides and their laboratory reconstruction which involved primarily shotguns and handguns, indicate that reconstruction can be immensely useful to interpretation of the gunshot residue distributions on a suspect's or victim's hands. This reports outlines the basic experiments performed to relate the residue emission from the gun to the deposits found on the firing hand(s) and a description of the reconstruction technique that uses a target to simulate a human body. The technique can determine the specifics of a victim's hand position at the time of firing and which hand was used to pull the trigger. Because the technique is sensitive to the nature of the grasp of the firing hand and of the supporting hand, in the case of a shotgun, it has been possible in all cases to date, to determine which one of the potential eight hand positions existed at the time of shooting.

At present, characterization of topography of paint fragment samples in criminal cases is being undertaken by use of light microscopy. Wet chemical analysis and a wide range of spectral techniques are being used for elemental identification. Electron optical instruments have been developed that are capable of both topographical and elemental analyses. For example, the scanning electron microscope (SEM) can provide topographical information with greater depth of focus, higher magnification, and higher resolution than optical microscopy. Additionally, the electron beam can be used to excite characteristic X-radiation from the sample, theleby providing a wavelength spectrum for elemental identification and chemical species distribution in the sample.

Recent applications of the scanning electron microscope (SEM) have been in areas such as paint samples evaluation [1,2] and firing pin impressions [3,4], These have provided useful additional information to the forensic scientist. This investigation was conducted to further expand the applicability of the SEM and the developed imaging techniques for use on other forms of physical evidence. Specifically, striations on copper-jacketed bullets and contaminant particles recovered from personal articles (clothing, shoes, etc) were chosen.

Automotive paint fragments are one type of physical evidence material which has been examined by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS) [1,2]. The SEM-EDS can add to the information which can be obtained from a paint sample because the paint contains both topographical features and chemical composition data. Previous research has been undertaken to try to understand the nature of the variables involved and the criteria of data evaluation [1–4]. While these studies showed the applicability of the SEM to the forensic science analysis of paint fragments, the questions of reproducibility of the data obtained and of reliability as an identifying technique were not definitively answered.

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