How forensic scientists will uncover secrets in future
Dust contains biological and chemical signatures that act like a fingerprint for a specific location. Forensics could even be used to solve crimes in the future.
Criminals will soon no longer be able to "make off" so easily: Airborne soil particles are as characteristic of specific locations as a fingerprint, as the dust contains biological and chemical signatures. Even small traces of dust of only around three micrograms can now provide potential evidence of the location or origin of material, personal items and objects after forensic analysis.
Australian forensic scientists at Flinders University have investigated new technical methods by researching the chemical and biological profiles of various sites in South Australia. Their work on the Project "InFoDust" opens up dust as a tool for forensic investigation. According to a scientific article published by the team in an international forensics journal, dust analysis is so informative that it could soon serve as a standard tool for forensic casework.
"Dust is everywhere.
"Dust is everywhere. It sticks to clothes and objects after you've travelled, leaving a trail that shows where you've been," explains forensic researcher Nicole Foster from Flinders University, who currently works at the Smithsonian Environmental Research Institute in the USA.
With this knowledge, she and her team conducted a field experiment in which they left objects at various locations in South Australia. Dust accumulated on the discarded objects, which the researchers then analysed. In doing so, they checked whether the chemical and biological profiles were significantly different at the various locations. While the chemical signatures were more likely to be inorganic particles, the biological signatures could include DNA fragments from fungi and bacteria.
The team found that the dust recovered from each object did indeed contain chemical and biological profiles that were unique to each site. However, these profiles were variable within sites and over time.
With her employees, Foster provides fundamental evidence that dust is well suited as a medium in forensic reconnaissance. Before this tool can be integrated into forensic casework, there is still a lot of work to be done. For example, Foster's colleague and co-author Duncan Taylor explains that DNA fragments from bacteria and fungi in soil "can be used as key evidence" to establish a link to the crime scene. Dust, however, is relatively new to the field of forensics. The scientist reports that of all the dust samples collected in South Australia, the team was able to correctly predict the origin of 67 per cent of the samples based on the bacterial profiles and 56 per cent based on the fungal profiles. Conversely, however, this also means that the error rate is still relatively high.
It is likely that biological differences within the individual sites led to this high error rate, Taylor explains to the American Association for the Advancement of Sciences. The team and he had found that the variability at one site was no greater than between sites. "This means that bacteria and fungi can be unique to certain locations, which is why dust should be an important tool for forensic investigation in the future," says Taylor.
Although there is still a lot of work to be done in this area, the researchers conclude that both chemical and biological analyses of dust samples offer great potential for forensics. Various government and scientific institutions have financed the "InFoDust" project with third-party funds; it was developed in partnership with a South Australian national defence programme, among others. As the full name of the project reveals, this research is probably primarily in the service of military reconnaissance, internal security and potential measures against terrorism - the acronym "InFoDust" stands for "The Intelligence and Forensic potential of Dust traces for Counter-Terrorism and National Security".
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Spectrum of Science
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