• Question: What type of data can be found in makeup that can be used for evidence? And what type of kung fu do you do? (I do kung fu too :D)

    Asked by anon-346446 to Katy on 10 Jan 2023.
    • Photo: Katy Bruce

      Katy Bruce answered on 10 Jan 2023:

      Hi! Thanks for your question. The type of data I can get from the makeup samples I look at depends on the technique I’m using at the time.

      When I use X-ray fluorescence I can only see elements (and not molecules) and only those which are larger than oxygen, so it’s good for looking at minerals like titanium dioxide or iron oxide, which are used as pigments in makeup. But if I use Raman spectroscopy, I can see both minerals and organic substances such as waxes, oils or silicones, and this is molecular data not just elemental data. If I use Infrared spectroscopy I can see very similar data to Raman data but due to the way the technique works I get slightly different data – often called complementary data – which helps me get a much broader idea of what the makeup contains!

      I can also use light microscopy which obviously allows me to look at the sample, but this can also be really useful as you can determine things like colour, presence or absence of particles, sizes and shapes and distribution of particles (morphology), and the appearance of the surface of the makeup (topology). I can take that a stage further and use scanning electron microscopy (known as SEM) to look at very magnified images of the samples, which can help discriminate between visually similar samples. Have a look at some SEM images on google, they’re amazing!

      Unfortunately though, due to the complexity of makeup formulations and factors such as transfer, persistence, contamination, layering of products, evaporation, skin absorption, etc, the analysis of makeup in a crime scene context is actually really difficult!!

      Not sure if that answers your question or has confused you?! 🤔

      Oh and that’s cool you do Kung Fu too! I suspect you’re way better than I am! Our club’s style is actually freestyle karate so it’s a mix of karate with kickboxing and a dash of Kung Fu, rather than proper Kung Fu. We learn katas with Fung Fu moves in them like dragon, snake, crane, bear, mantis and tiger! 🐯

Comments

  • Photo: David

    David commented on :

    Trace evidence can be found for example hairs and skin cells as we constantly lose skin from our body’s surface.

  • Photo: Lorna

    Lorna commented on :

    Make up is a complex trace material type and would require a multi mode analysis approach using a range of methods from light microscopy, SEM EDS for detailed semi quantitative elemental compositional analysis, FTIR / RAMAN for organo mineral profiles, , XRD for inorganic mineral composition, GC or GC MS for organic profile analysis quantification, plus a good database of I text sample data for comparison, to put any comparisons between the questioned sample with the source sample!! Context is vitally important in forensic science. Allows alternative propositions to be tested.