Forensic Department "Environment-Fire-Explosives"
Forensic Expert - Forensic Department "Environment-Fire-Explosives", IRCGN
Staining involves an ink projection on banknotes whenever an attack is detected. Several ink colorations can be used. Those intelligent systems for the neutralization of banknotes (IBNS) dissuade robbers from attacking an ATM and also they secure the money transports. In case of an aggression, the system triggers the neutralization of the banknotes by making them unsuitable for any use.
Since 2014, the legislation in effect has reinforced itself by demanding that the staining ink contains chemical or biological tracers (discriminating for each cash box), which can be analysed by the IRCGN. By using a banknote coming from stolen and stained with trace ink funds, we are able to determine the banknotes origin.
The IRCGN has put up in place a robust analytical strategy allowing the identification of the source of several hundreds of stained banknotes.
This strategy associates various analytical methods. Identification of the stained ink type (type and supplier) is obtain thanks to a comparative analysis using LC-HR/MS of the organic components contained in the stained ink available on the market. Depending on the results, analysis promptly heads towards Scanning Electron Microscope (SEM) (mineral tracer) and towards sequencing and genotyping techniques (synthetic DNA tracer). All the methods involved in this strategy received an accreditation according to the norm ISO CEI 17025.
The two concrete cases presented allow us to estimate the analytical strategy established: for the first one the visual macroscopic observation of stained banknotes implies that they have undergo an unstained attempt. This being noted, a new issue is raised: has the cleaning agent had an impact on the incorporated tracers in the stained ink ? Can the origin of the banknote still be determined ?
Indeed, decoding by analysing the unique tracer inside each banknotes cassette reinforces the relevance of the IBNS by providing key elements in an judicial investigation. The second concrete case corresponds to an illustration. How an investigation opened for infractions having a terrorist aiming changes dramatically in an armed robbery in a post office ?
Stained inks are relevant devices whose resistant formulation guarantee the neutralisation of the banknotes nevertheless the traceability can be weakened. Several points that need to be working on in order to continue the fight against delinquents.
Colorant, Stained Ink, Taggants