Following a chemical incident involving chemical warfare agents or more broadly, chemical
weapons, there are two possible approaches in dealing with the traditional forensic
analysis of contaminated exhibits. The first is to analyze the contaminated items under
safe conditions (i.e. in laboratories dedicated to the handling of such substances), while
the second relies on item decontamination prior to processing them in traditional forensic
laboratories. One of the main limitations of the latter is the possible degradation or
destruction of traces caused by the decontamination process. Hence, it is crucial to have
as much information as possible on the impact of different decontamination agents and
procedures on traces. This research presents experimental results on the recovery of fingermarks
on glass after the application of decontaminants typically used in case of chemical
incidents. The impact of 11 decontaminants on fingermarks deposited on glass and
on the subsequent enhancement with cyanoacrylate and Small Particle Reagent (SPR)
was evaluated (by visual examination) by four evaluators. The results of the study demonstrated
that the persistence of fingermarks on glass is highly dependent on the type
of decontaminant used. Decontamination agents based on the principle of nucleophilic
substitution to neutralize toxic chemicals allowed good subsequent development of fingermarks
with SPR. Powdered decontaminants did not show any indication of alteration
of fingermarks, whereas decontamination with oxidants leads to variable results.