New possibilities of post-blast residues analysis in forensic science

摘要

Non-standard and homemade explosives can represent a certain risk for security units as the result of their, practically,unlimited variability both in content and in the construction of explosive objects. Identification of matters that havealready gone through an explosion can be problematic. The number of different combinations is really high and it is notdifficult to obtain precise and functional instructions for production and the construction itself is quite easy. That is whya few-years-long project was commenced the aim of which is to obtain new complex analytical data of improvisedexplosives residues. A whole range of experimental substances was selected for experiments including liquid explosivesthat can be prepared fast and easily. Experimental explosions are carried out on a freshly ploughed soil of dumps of openpit mines (where explosives are not used for mining) to avoid possible contamination. After the explosion, the residuesfrom the stub are analyzed in a standard way and a complex analysis of both organic and inorganic phase is carried out.For selected non-stoichiometric mixtures, explosion characteristics are further calculated unless they are already known.Analysis of post-blast residues of non-standard and homemade compounds is usually started with the SEM analysis.Concerning the character of the data obtained in the frameworks of the project, a special information system isprogrammed. All the data obtained are entered into this system. The information system is a database layer allowing datato be entered, classified and analysed. The system shall serve the Forensic Laboratories and Expert Services of the Policeof the Czech Republic and other specialized units.