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Forget dusting, tiny crystals make fingerprints GLOW at crime scenes

New technique using crystals and UV lights was developed by CSIRO
Process makes fingerprints glow in 30 seconds and preserved prints
Invention could speed up the time it takes to lift prints after burglaries

Published: 04:15 EST, 20 October 2015 | Updated: 07:04 EST, 20 October 2015

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Investigators have dusted for fingerprints at crime scenes for over a century, but a new technique could make criminals’ prints stand out more easily.

An Australian researcher has developed a new process to make fingerprints ‘glow’ under UV light within 30 seconds.

His invention could speed up the time it takes to lift prints after burglaries, for example.

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An Australian researcher has developed a new process to make fingerprints ‘glow’ under UV light within 30 seconds (shown). His invention could speed up the time it takes to lift prints after burglaries, for example

The technology uses liquid containing tiny crystals, which when painted onto surfaces, picks out details of prints on a molecular level.

The metal organic framework (MOF) crystals are cheap, react quickly and are able to emit a bright light.

This luminescent effect creates greater contrast between the latent print and surface, meaning investigators could more quickly and easily photograph prints at a crime scene and send them for further investigation.

The technique was developed by Dr Kang Liang at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Dickson, near Canberra.

The technology uses liquid containing tiny crystals to pick out details of prints on a molecular level. This luminescent effect creates greater contrast between the latent print and surface, meaning investigators can more quickly photograph prints at a crime scene (example shown) and send them for further investigation

Police officers have used specialist brushes and powders to lift fingerprints from crime scenes for over a century (illustrated with a stock image). Particles of the powder adhere to residue left by friction ridge skin on the fingers and can then be removed so a copy of the fingerprint is obtained

HOW DOES THE NEW FINGERPRINT TECHNOLOGY WORK?

A liquid containing tiny metal organic framework crystals is applied to non-porous surfaces thought to have fingerprints on.

The liquid picks out details of the prints on a molecular level.

The fingerprints glow when a UV light is shone on them.

This luminescent effect creates greater contrast between the latent print and surface than traditional dusting techniques.

The clear prints mean investigators could more quickly and easily photograph prints at a crime scene and send them for further investigation.

He believes it could be used for more challenging evidence where conventional ‘dusting’ is not appropriate.

‘While police and forensics experts use a range of different techniques, sometimes in complex cases evidence needs to be sent off to a lab where heat and vacuum treatment is applied,’ he explained.

‘Our method reduces these steps, and because it’s done on the spot, a digital device could be used at the scene to capture images of the glowing prints to run through the database in real time.’

His study, published in the Advanced Materials journal, shows that tiny crystals rapidly bind to fingerprint residue, including proteins, peptides, fatty acids and salts, creating an ultrathin coating that’s an exact replica of the pattern.

Dr Liang said: ‘Because it works at a molecular level it’s very precise and lowers the risk of damaging the print.’

He told Mashable that once a print has been revealed, the liquid helps to preserve it.

'In our lab, it stayed for up to three months and the pattern was still very fine.'

The method has been tested on non-porous surfaces such as windows, wine glasses, metal blades and plastic light switches, and has been found to be effective.

However, Dr Liang is still working on making it possible to lift prints from fabric and paper.

If this is possible, the technology could replace conventional finger dusting or be used alongside it to save time and costs during investigations.

The new method using liquid with crystals inside has been tested on non-porous surfaces such as windows, wine glasses, metal blades and plastic light switches (shown) and has been found to be effective

Dr Liang explained he was inspired to create the new system after his home was burgled.

‘When my house was broken into I saw how common practice fingerprinting is for police,’ he said.

‘Knowing that dusting has been around for a long time, I was inspired to see how new innovative materials could be applied to create even better results.

‘As far as we know, it’s the first time that these extremely porous MOF crystals have been researched for forensics.’

The crystals are cheap and emit a bright light, while not creating any dust or fumes, reducing mess and the risk of inhalation.

Dr Liang believes the crystals could also have other valuable applications including new biomedical devices and drug delivery.

CSIRO is looking to partner with law enforcement agencies to apply the new technique, and Dr Liang believes the crystals could also have other valuable applications including new biomedical devices and drug delivery.

CSIRO is looking to partner with law enforcement agencies to apply the new technique and see whether it makes catching burglars, for example, easier. A stock image of a burglar is shown