New fingerprinting method

Researchers in the UK have revealed new methods whereby fingerprints can be found that change with age, smoking habits, drug use, and even some fish sex tools. certain people.

New technology can detect fingerprints that cannot be seen with the naked eye (Photo: bbc) New research also promises to get good quality 'forgotten' fingerprint copies for days or even only weeks at the scene. The new study aims to find fingerprints on guns or bomb debris, often in the most difficult-to-find evidence.

Under the direction of Dr. Sue Jickells of Kings College (London, UK), this study is reaping positive results, through observing the chemical composition of fingerprints and considering them transform how over time. Dr. Jickells said that when people touch anything, a lot of 'sticky' materials are fat molecules (ie lipids): 'There are lots of lipids in the fingerprints, and there are A lot of possibilities to find them '.

Such a lipid, called squalene or a precursor of cholesterol, is heavily present on fingerprints. Squalene will decompose after a certain period of time, just like neutral and non-neutral fatty acids stick to certain surfaces when people touch them. This makes older methods unable to regain fingerprints after some time. Exploring how knowledge of these organic compounds decomposes, Dr. Jickells's team devises ways to collect good quality evidence from relatively old fingerprints, and show that fingerprints can be used. to expose clues about objects with fingerprints left.

Everyone knows that adults, children and the elderly leave different types of organic compounds in fingerprints. The new finding shows that the body of the drug users inevitably secrete part of the chemical (through the metabolic mechanism) they used. For example, smokers' bodies secrete cotinine, a chemical made when the body smokes and decomposes nicotine. Currently the research is continuing to "collaborate" with detox centers and hospitals that have methadone analgesics to see how this use changes the fingerprints.

An additional study conducted by Professor Neil McMurray and colleagues at Swansea University (Wales) also aims to collect more fingerprints in the cases. McMurray's work shows that it is possible to recover fingerprints on metal surfaces (shells, bombs .). The fingerprints left on guns and bomb casings tend to be left behind by sweating, and therefore are not easily recovered by techniques using powders and other chemicals. Instead, Professor McMurray measured tiny electrochemical reactions that took place when fingers touched the metal.

A device called Kelvin Probe (Scanning Kelvin Probe) is used to measure extremely small changes in voltage caused by these reactions . Fingerprint samples were found even on experimental metals to a temperature of 6000C. This technique has proven to be effective for iron, steel, aluminum, zinc and brass, and can even adapt to the curves found on cartons. Professor McMurray said: In the end, research can develop a handheld device, which helps analyze fingerprints at the crime scene. Research on fingerprints was presented at a conference in London, organized by the Council for the Study of Physical Science and Technology, to highlight the importance of 'Science can support investigation work like how'