New forensic technique for analysing lipstick traces

August 8, 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: Shedding new light on cancer

Related Stories

Shedding new light on cancer

January 22, 2010

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

Chemists offer law enforcement crime solving tool

June 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 and ...

Recommended for you

Making polymers from a greenhouse gas

July 28, 2015

A future where power plants feed their carbon dioxide directly into an adjacent production facility instead of spewing it up a chimney and into the atmosphere is definitely possible, because CO2 isn't just an undesirable ...

New material opens possibilities for super-long-acting pills

July 28, 2015

Medical devices designed to reside in the stomach have a variety of applications, including prolonged drug delivery, electronic monitoring, and weight-loss intervention. However, these devices, often created with nondegradable ...

Bleach a possible key to life on earth

July 23, 2015

Hydrogen peroxide - commonly used as hair bleach - may have provided the energy source for the development of life on Earth, two applied mathematicians have found.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.