Evidently quicker

Forensic scientists could analyse large quantities of evidence far more quickly and accurately using a technique, currently under development in the UK, to enhance the sensitivity of sample imaging.

ATR (Attenuated Total Reflection) infrared imaging could allow crime investigators to analyse large surface areas of human skin, clothes, banknotes and explosives, according to project leader Dr Sergei Kazarian of the chemical engineering and chemical technology department at Imperial College. Forensic scientists could even detect particles resting in the ridges of a human fingerprint.

The technique involves focusing infrared radiation onto the end of an element. This element is then pressed against the material being analysed. When the infrared radiation reflects through the element, it penetrates the material and generates a unique image of its surface by revealing spectral differences between elements.

The project is being part-funded by the Forensic Science Service and, said Kazarian, the use of infrared spectroscopy could herald a breakthrough in the way forensic scientists are able to analyse data.

‘The real difference this will make is that, where time is vital, large quantities of material such as clothing can be quickly and accurately analysed,’ he said. ‘It is incredible how much quicker and easier it could make things.’

With existing forensic spectroscopic equipment, samples can be analysed only in small sections, meaning the study of a relatively large surface area, such as a banknote, could last hours or even days. With the use of ATR-IR imaging, the surface area that can be analysed is only restricted by the size of the detector, massively increasing the volume of material that can be analysed.

During the two-year project the researchers aim to tackle the main problem facing the technique, the difficulty of judging its sensitivity. Already several large forensic equipment companies have shown an interest, Kazarian said.

The team also plans to use the ATR-IR imaging technique alongside more conventional ‘tapelifting’ forensic science at crime scenes and for analysing gunshot residues, as the technology allows an unprecedented close-up view of the individual particles. The research has recently been awarded funding under the EPSRC’s Think Crime initiative, and will begin in September. The project also involves instrument developer Bruker UK and infrared spectroscopy specialist Specac, part of the Smiths Group.