New forensic technique for analysing lipstick traces

Aug 08, 2013

(Phys.org) —A study by forensic scientists at the University of Kent has established a new way of identifying which brand of lipstick someone was wearing at a crime scene without removing the evidence from its bag, thereby avoiding possible contamination.

Using a technique called Raman spectroscopy, which detects laser light, will be able to analyse lipstick marks left at a crime scene, such as on glasses, a tissue, or , without compromising the continuity of evidence as the sample will remain isolated.

Analysis of lipstick traces from crime scenes can be used to establish physical contact between two individuals, such as a victim and a suspect, or to place an individual at a crime scene.

The new technique is particularly significant for forensic science as current analysis of lipstick traces relies on destructive or human opinion.

Professor Michael Went of the University's School of Physical Sciences said: 'Continuity of evidence is of paramount importance in forensic science and can be maintained if there is no need to remove it from the bag. Raman spectroscopy is ideal as it can be performed through transparent layers, such as evidence bags. For forensic purposes Raman spectroscopy also has the advantages that microscopic samples can be analysed quickly and non-destructively.'

Raman spectroscopy is a process involving light and vibrational energy of . When a material - in this case lipstick - scatters light, most of the light is scattered at its original wavelength but a very small proportion is scattered at altered wavelengths due to changes in vibrational energy of the material's molecules. This light is collected using a microscope to give a Raman spectrum which gives a characteristic vibrational fingerprint which can be compared to spectra of lipsticks of various types and brands. Hence it is possible to determine identity of the lipstick involved.

Research into applying the same method on other types of cosmetic evidence, such as foundation powders, eye-liners and skin creams is also underway.

The study, titled 'Application of Raman spectroscopy for the differentiation of lipstick traces', Fatma Salahioglu, Michael J. Went and Stuart J. Gibson, is published in the Royal Society of Chemistry journal.

Explore further: Novel 'butterfly' molecule could build new sensors, photoenergy conversion devices

add to favorites email to friend print save as pdf

Related Stories

Chemists offer law enforcement crime solving tool

Jun 19, 2012

(Phys.org) -- University at Albany researchers have developed a method to determine the caliber and type of weapon used in a crime by analyzing gunshot residue (GSR). Using near-infrared (NIR) Raman microspectroscopy ...

Shedding new light on cancer

Jan 22, 2010

(PhysOrg.com) -- Researchers at the University of St Andrews have developed a powerful technique that could allow earlier cancer detection.

Recommended for you

Protein glue shows potential for use with biomaterials

17 hours ago

Researchers at the University of Milan in Italy have shown that a synthetic protein called AGMA1 has the potential to promote the adhesion of brain cells in a laboratory setting. This could prove helpful ...

Breaking benzene

Aug 27, 2014

Aromatic compounds are found widely in natural resources such as petroleum and biomass, and breaking the carbon-carbon bonds in these compounds plays an important role in the production of fuels and valuable ...

User comments : 0