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Development of latent fingermarks on thermal paper: Preliminary investigation into use of iodine fuming

Development of latent fingermarks on thermal paper: Preliminary investigation into use of iodine fuming. Om Prakash Jasuja ; Gagandeep Singh . Forensic Science International, Volume 192, Issue 1, Pages e11-e16, 20 November 2009. Persent by Pol.capt Nanthakarn Taljinda. Introduction.

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Development of latent fingermarks on thermal paper: Preliminary investigation into use of iodine fuming

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  1. Development of latent fingermarks on thermal paper: Preliminary investigation into use of iodine fuming Om Prakash Jasuja; GagandeepSingh. Forensic Science International, Volume 192, Issue 1, Pages e11-e16, 20 November 2009 Persent by Pol.capt Nanthakarn Taljinda

  2. Introduction Thermal paper • Its extensive use in the modern day life • Introduced by National Cash Register Company in 1968 • Reaction Between leuco dyes and co-reactants

  3. Introduction - Reaction involves openingring structure - Heat black - Substituted fluoran different colors

  4. Introduction Various techniques to develop • - Ninhydrin • 1,8-diazafluoren-9-one (DFO) • dimethyllaminocinnamaldehyde (DMAC) • - Metallo-porphyrin compound [(TPP)Sn(OH)2]

  5. Iodine fuming Advantages : • Simple method, is inexpensive, fast and reversible • Non-destructive paper or any writing on the paper • Developed fresh as well as age latent fingermarks

  6. Iodine fuming Disadvantages : • The prints are not more than 1-3 day old • Iodine prints are not permanent and will fade, it necessary to photograph the prints immediately

  7. Material and method • Type of thermal papers • Mitsubishi fax paper • Oddy fax paper • D.P. Print paper • ATM paper receipts

  8. Material and method Donors 10 donors their finger gentle rubbing of the cheeks or forehead (sebaceous) 10 Donors their wash hands(eccrine) Donors were placed on thermal papers UV : 5-10 min Kept in dark Iodine fuming photograph photograph

  9. Results and discussions Permanency is dependent upon the type of thermal papers Mitsubishi and Oddy fax paper > ATM paper and D.P. print paper

  10. Results and discussions Mitsubishibrandafter 475 days

  11. Results and discussions Different types of thermal paper resulted in different colored fingermark Mitsubishi , Oddy, ATM receipts green / greenish black D.P. print paper black / brown / yellowish

  12. Mechanism of the fingermark development Iodine is electron-accepting oxidize leuco dye open lactone ring color formation

  13. Mechanism of the fingermark development

  14. Develop fingermark of iodine fuming UV:Dark

  15. Formation of different color fingermarks upon reaction with iodine Green Green color is produced by presence of two tertiary amino group at 2’ or 6’ positions 2’-n-butylamino-6’-diethylaminofluoran

  16. Formation of different color fingermarks upon reaction with iodine Black Black coloris produced by methyl group at 3’-position 2’-anilino-6’-diethylamino-3’-methylfluoran

  17. Formation of different color fingermarks upon reaction with iodine Brown Brown coloris produced by replacement of amino group at 2’-position with azomethine group e.g. 6’-diethylamino-2’-ethyl-lidenaminofluoran

  18. Develop fingermark of iodine fuming Develop fingermark of iodine fuming a) Sebaceous : b) Eccrine

  19. Develop fingermark of iodine fuming i) Oddy brand : ii) Mitsubishi

  20. Develop fingermark Right: by DFO Left: by iodine fuming ATM paper

  21. Develop fingermark of iodine fuming 1 year old

  22. Conclusion • - Developed fresh as well as age latent fingermarks • No Background • Permanent • Clear and legible fingermarks • Oxidation of leuco dyes • Various color • - It is sensitivity sebaceous marks

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