BAWC 2016 Email Version
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Transcript of BAWC 2016 Email Version
www.derby.ac.uk
Who am I?
• BSc (Hons) Forensic Science Student
• Graduate in July with predicted 1st Class (hopefully!)
• Aspirations for a career in the Wildlife Crime sector
• Combination of my two passions: Forensic Science & Wildlife!
• Particular interest in protecting birds of prey
• Lifelong member of the RSPB and Norfolk Wildlife Trust
www.derby.ac.uk
• Red and Green magnetic fluorescent fingerprint powders deemed most suitable for feathers• Black magnetic powder most suitable for the surface of the eggs
Previous Research
www.derby.ac.uk
Definitions• Research focused on the visualisation of latent fingermarks
– Latent: Generally difficult to visualise (invisible); Principle component is sweat;
Vast majority of all fingermarks
• Fingermark or Fingerprint?– Fingermark: Impression left by the friction ridges of a human finger
(Non-Fingerprint Experts)
– Fingerprint: Impression left by the friction ridges of a human finger (Qualified Fingerprint Experts Only!)
• Ridge Detail: ridge flow and specific ridge characteristics
www.derby.ac.uk
Methods• Fingerprint powders and Superglue fuming
• Powders observed using different wavelengths of light and their corresponding filters
• Superglue fuming followed by Basic Yellow 40 staining
• Fluorescent observed under blue light (430-470nm)
• Used a grading scale to determine the quality of the developed print
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Results
Feathers• Red magnetic powder enhanced
88.6% of fingermarks
• Green magnetic powder enhanced 84.3% of fingermarks
• Mainly low grade marks (some ridge detail present)
• Finer weave count of feather = better quality ridge detail
• Least Successful: White magnetic powder and aluminium powder
Eggs• Black magnetic powder enhanced
95.8% of fingermarks
• High number of high grade fingermarks developed
• High grade marks = more ridge detail present
• 100% enhancement on raptor eggs (Goshawk, Barn & Long-Eared Owl)
• Least successful on raptor eggs: aluminium powder
www.derby.ac.uk
Our Research• Replicated techniques
• Deposited fingermarks on the top, underside and quill tip of the feather
• Tested more colours of fluorescent fingerprint powder
• Trialled the combinations of powder and wavelength of light to determine the best contrast
• Used Superglue fuming followed by two types of stain
• New methodology
• Examined efficiency of Ninhydrin & DFO
• Additionally tested the effect of Small Particle Reagent (SPR)
• Looked at the effect of separation/repair
• Ensured each fingermark was deposited with the same amount of sweat and pressure
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Results – Magnetic powderGreen Powder + UV light: Dark Feather
Green Powder + UV light: Waterfowl Feather
Combination worked well on three feather types:
• A white, waterfowl feather
• A patterned Tawny Owl feather
• A dark, banded feather
The darker the feather, the better the contrast!
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Results – Superglue Ninhydrin & DFO
• Waterfowl Feathers– Basic Yellow 40 Stain –
Enhanced 7 out of 8 marks under blue light (430-470nm)
– Saffranin Stain – One mark (no ridge detail) under blue light
• Tawny Owl Feathers– Basic Yellow 40 Stain – No
enhancement– Yellow SPR – One mark, no ridge
detail– Green Fingerprint Powder + UV –
Enhanced all marks
• Concluded an unsuccessful “wet” treatment
• Chosen due to being fingermark development techniques for porous surfaces
• Feathers were dyed by the Ninhydrin reagent (purple) with no fingermark development
• No fingermarks were developed under DFO
• Concluded as unsuccessful development techniques for feathers
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Results – Small Particle Reagent (SPR)
• Liquid reagent caused problems with non-waterproof feathers
• Feathers needed to be re-spread and dried prior to examination
• Developed low grade prints (limited ridge details)
SPR + White Light: Tawny feather
SPR + UV Light: Tawny feather
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Effects of Separation• Two methods tested:
– Depositing a mark followed by separation of the feather – Separating the feather followed by depositing the mark
• Marks were enhanced with green fingerprint powder and SPR
• Detail was lost if mark separated after SPR enhancement
• Green fingerprint powder could be separated
• Separation and subsequent repair dependent on the texture of the feather
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Developed Mark, Separated Mark & Repaired Mark
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Conclusion
• Green magnetic fingerprint powder examined under UV light (350-380nm) most successful technique
• Small Particle Reagent most successful “wet” treatment
• Location of the mark on the feather is an important factor– Further from quill = clearer, more detailed fingermarks
• Texture of the feather effected enhancement and separation– Softer, “fluffier” feathers = less clear fingermarks– Thicker barbs of feather = more likely to be separated and repaired