Examination of Firearms Review: 2007 to 2010 - Interpol

One technique to decontaminate evidences contaminated with anthrax spores
is to expose the evidence to formaldehyde gas. A new protocol for such
decontamination was developed that allows the destruction of viable spores
without affecting the successful recovery of latent fingerprints. 136
The effect of electron beam irradiation – used for disinfecting letters
contaminated with biological agents – on various writing inks was
investigated, showing only little degradation of the inks. 137 A similar study
sought to determine whether gamma irradiation could be used as an effective
biological decontaminant. Its effect on the recovery of latent fingermarks and
DNA was tested and established that gamma irradiation was a viable
decontamination option, 138 although an earlier study indicated that the
irradiation process can have a detrimental effect on the success of certain
visualization reagents. 139
The efficacy of two decontamination techniques (chemical and physical)
designed for the removal of radiological material dispersed on documents
have been assessed. The impact that these procedures have on the
development of latent fingermarks and the forensic analysis of the inks on
these documents has also been studied. It was found that slight changes in
the colour and chemical composition of a variety of document inks and a
destruction of fingermark ridges occurred after chemical decontamination, but
physical decontamination had no impact on these parameters. 140
5.6 Contaminated bodies
Bodies contaminated with CBRN agents provide their own challenges. The
bodies themselves may require decontamination, but internal organs may still
retain some of the toxic agent. A guide for medical examiners and coroners
has recently been issued, providing information and suggestions about the
principles involved in decontamination procedures as they may impact on
evidence collection and/or the temporal sequence of death investigation. 141
The risks associated with contaminated CBR fatalities depend on the nature
of the hazards and a number of environmental factors encountered during
handling. The UK Government has developed body process pathway
algorithms to provide guidance to those involved at all stages of contaminated
mass fatalities. 142 The situation is even more complicated for radioactively
contaminated fatalities, where regulations about the transport and storage of
radioactive material may apply. 143
The requirement for identification of the deceased may necessitate the
removal of contaminated samples to a DNA laboratory for processing. The
potential risks and difficulties associated with processing samples of this type
have been reviewed. 144
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