Forensics experts are building chemical profiles of popular fragrances where they hope to use them to identify scents left on items touched by criminals. By building a ‘scent profile’ of the person behind a crime, it can help to narrow down lists of suspects and even be used as evidence in court. 

Alison Davidson, a researcher at Staffordshire University’s department of forensic and crime science, is leading the work in the hope that it can be used by police forensics teams.

She said: ‘Suspects can be smothered in fragrance and I am trying to find chemicals that can give some extra information. ‘You can get quite a complex mixture of different personal care products that can be used together to narrow down a list of suspects or build up a picture of a perpetrator.

‘For example, Chanel No 5 is famous for using a particular aldehyde, so if I can see components that are typical of Chanel it might be possible to say a suspect comes from a certain socio-economic background. Similarly Lynx tends to be used by younger men.

‘If we were to see some Gillette fragrances in there too, for example, then we can start to unpick a bit about who they are.’ Mrs Davidson, who presented her findings to a recent meeting of the International Fragrance Association UK Fragrance Forum, is attempting to develop the technique so it can be submitted as robust evidence in court.

She said samples of scents can be easily gathered from the clothing of victims or from swabs taken off hard surfaces. These can then be analysed in the laboratory for chemical signatures that match those found in beauty and personal hygiene products.

‘I am concentrating on what compounds we can detect and what might be significant,’ she continued. ‘Ultimately I am not really interested in whether the samples we get actually smell or not – I’m looking for the chemical patterns to see if they can be matched with anything. ‘Scent evidence is never going to be as robust as DNA evidence, but you can get something a lot quicker and cheaper than you can with DNA. ‘Used together with other forensic methods it can be another piece of evidence in the puzzle – it is another tool in the toolbox.’

Sniffer dogs have been used by police in criminal investigations for decades and are often able to identify individuals from their scent even if they have changed soaps. Forensic scientists have been attempting to replicate this by using electronic equipment that can analyse the chemical components of an odour. They hope that by identify key compounds from the sweat left behind by criminals, it can be used as evidence against them. They also hope that chemical markers in the sweat could also be used to build up lifestyle profiles of suspects, indicating whether they smoke, their diet, sex and even emotional state.

Professor Richard Brereton, from Bristol University’s Centre for Chemometrics, has been helping to develop a way of identifying individuals from their scent by looking at 44 chemical compounds secreted by the human body. Another team at the University of Pennsylvania, who are working with defence firm Lockheed Martin, have also developed a new technique for analysing odour profiles given off in sweat that they hope will lead to new handheld devices.

Dr Charlie Johnson, who led the work which is published in the Journal of Forensic Science and Criminology, said: ‘We have demonstrated a viable technology for fast, cheap, all-electronic analysis of known odor profiles. ‘Humans emit a variety of volatile organic compounds in urine, sweat and other bodily fluids.

‘Techniques to quantitatively analyze volatile organic compound profiles in sweat and other bodily fluids could find applications in disease diagnostics, health and wellbeing monitoring, and even for detection, identification or tracking of individuals.’

Source: Daily Mail