Whether it’s for solving a crime or preventing one, high energy particles can be used to help uncover forensic evidence that other methods alone may miss or aren’t able to detect. While these analytical techniques are common in materials research, they only recently started gaining ground in criminal investigations. To help pave the way for their wider use, a workshop on enhancing accelerator-based analytical techniques for forensic science was recently organized by the IAEA in partnership with the Abdus Salam International Centre for Theoretical Physics (ICTP) and held in Trieste, Italy.
“Crime is a worldwide threat, and we need a global perspective and the right combination of tools to effectively protect people. One of those tools is accelerators,” said Francesco Saverio Romolo, a former police officer at the Italian National Police and now a professor at the University of Bergamo and expert with more than ten years of teaching and research experience in forensic science. “Based on the positive feedback from the participants, I am sure this workshop will be an important step toward making accelerator-based techniques a more regular part of forensic science and supporting the global effort for a safer future.”
The workshop brought together professionals from diverse fields to help bridge the gap between research and real-world applications; experts presented accelerator-based techniques for forensics and trained scientists, who are looking to branch into or hone their skills in the field, and end-users, such as police forensics investigators, who want to learn about and potentially adopt these powerful methods. Participants also included technology manufacturers that, through further developing and refining instruments, can help advance work in this area.
For participants like Kwaku Godsway Banini, a research scientist and head of the Accelerator Research Center in Ghana’s Atomic Energy Commission, this workshop was a chance to get information to help branch out into this area of work.
“Forensic science using accelerators has not yet gained ground in Ghana. My laboratory is young, and I came to this workshop to learn from the experts and find out more about the fundamentals and different techniques, procedures, and materials,” said Banini. Ghana received an accelerator from the Netherlands in 2016 through a partnership agreement with the IAEA. “My colleagues and I intend to use what we have learned about accelerator technology to work with the government and other institutions to investigate and expose food fraud, fake cosmetics and substandard medicine in Ghana, to ultimately remove these unwholesome products from the market.”
Ion beam accelerators and synchrotrons
While there are different types of accelerators, ion beam accelerators and synchrotrons are two of the most commonly used in forensic science. These machines use electromagnetic fields to speed up ions or electrons to create a beam of charged particles or photons. Samples of forensic evidence are placed into the beam, where the particles or photons interact with atoms in the sample. These interactions release particles and/or radiation, like X-rays or gamma rays, which are then picked up and processed by a specialized detector. The results can then be used to determine the sample’s elemental and chemical composition, structure, age and even origin.
These details can support forensic investigations and monitoring of criminal activities, such as analysing gunshot residues, fingerprints and illegal drugs, as well as for checking authenticity of food, pharmaceuticals and cultural heritage artefacts, such as artwork and historical documents. The samples remain intact during the analysis, which means evidence or artefacts can then be further evaluated using additional methods to gather more information.
“Accelerators are complex machines that are expensive to use, but they offer vital analytical information at a level of precision that can be critical for certain analyses and for verifying or protecting important, high-value or priceless goods,” said Aliz Simon, an IAEA nuclear physicist specializing in accelerators. “The idea is that these techniques can complement other methods and support a problem-oriented approach, which means picking the most effective and economical combination of analytical techniques and tools for collecting forensic data.”
The workshop discussions and presentations provided an in-depth look at accelerator-based techniques, how they can complement various forensics methods as well as challenges and case studies on how to broaden their use. Sessions also covered strategies for effectively implementing these methods into forensics work and for preparing and handling forensic data to ensure results are accurate, credible and can hold up in court.