Fingerprints – one of the major source of evidence
Friction ridge skin impressions have been used for over a hundred years for the purpose of identification and still constitute the primary source of evidence in identifying perpetrators of crimes. The unambiguous and indisputable identification of people on the basis of fingerprints is based on their properties like uniqueness, immutability and irremovability. The friction ridges are covered with substances secreted by sweat glands (e.g. sweat, fat). Due to these compounds, fingerprints are being left behind when touching objects. The process of depositing fingerprints can be compared to the application of ink stamps. The difference is that fingerprints formed with a body’s natural secretions and sweat usually are invisible to the naked eye. To make them visible various methods are used.
In most cases these methods involve to the reaction of the appropriate reagent with a specific component of the latent-forming material or the adhesion properties of the agent to the latent-forming material. The choice of visualization methods depends on the type of surface on which the traces were deposited and also of their presumed age, environmental conditions and the conditions of its storage. Out of the wide range of trace visualization methods, the most effective ones are used in everyday laboratory practice. To detect as many traces as possible a number of sequential methods is often used together at the same time. But still new, universal, more sensitive and effective methods of visualizing traces are being sought.
How nanoparticles can help fight crime?
The advancements of nanotechnology widely contributed to conducting scientific research and development works using nanoparticles, i.e. the particles smaller than 100 nanometers, that means 10-9 meters. The results of the conducted research have been implemented in various fields of science, e.g. protective coatings, cosmetics, medicine or electronics, significantly evolving the quality of our lives. Due to their special e.g. luminescent properties, the research is ongoing on usage of nanoparticles to reveal latent fingerprints.
Nanoparticles could become a new generation tool for crime scene investigators and forensic experts combating various forms of crime including terrorism. As a result of using nanoparticles with high homogeneity and specific physicochemical properties, important in fingerprint examination, it is possible to improve the readability and the amount of revealed fingerprint latent fingermarks. It is also much easier to derive more on the fingerprint, which will directly contribute to increasing the efficiency of investigative services.
When selecting nanoparticles, their luminescent properties in a wide spectrum of VIS and UV light will constitute a primary criterion, which will eliminate the negative surface effect on the image of evidence.
Nanodetectors – successful and save!
The application of nanoparticles in revealing fingerprints is the opportunity in terms of significant increase in the variety of methods and their versatility. The miniaturization of particles entails changes in their physicochemical properties compared to products in a macro scale. This change is a result of a relatively large surface area of the nanoparticles compared with their volume, which could entail their higher reactivity or the appearance of luminescent properties. The wide range of luminescent properties of nanoparticles eliminates the negative effect of the surface on the readability of the traces. Nanoparticles can be used on both absorptive and non-absorptive surfaces, which provides for their versatility them the attribute of universality. This is a huge advantage when revealing marks on objects with different types of surfaces.
More importantly, the chemical substances located in nanodetectors are classified as a safe for health. Nanodetectors can replace the most popular fingerprint powder called argentorate (aluminum in the form of fine flakes), which is a neurotoxic metal.
Aim of the project
The main aim of the NANODAK Project is to increase the efficiency of fighting crime and terrorism by creating new methods of fingerprints visualization using nanoparticles.
Schedule of project works
Optimization of nanodetector characterization technology.
Selection of parameters for the production of suspensions containing nanoparticles.
Designing light sources dedicated to the activation of nanoparticles luminescence.
Preparation of nanodetector models for testing in laboratory conditions.
Research on nanodetector models and technical recovery of forensic evidence revealed by models.
Developing of nanodetector prototypes.
Research on nanodetector prototypes.
Validation of the nanodetection system.
Demonstration of nanodetection prototype system in real conditions.
Preparation of the developed solution technical documentation.
✔ increasing the possibility of revealing latent fingermarks by launching more sensitive and effective methods of traces visualization into practice
✔ ability to reveal latent fingerprints with one method on objects with characteristically different surfaces, which will contribute to shortening the time of crime scene investigation and evidential procedure
✔ using non-invasive methods, which will allow to perform other forensic examinations
✔ improving internal security by increasing law enforcement detection capabilities
✔ improving staff safety