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

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 - Heat black Substituted fluoran different colors - Substituted fluoran different colors - Reaction involves opening ring structure

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

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

6. Disadvan tages : 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 Iodine fuming

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

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

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 Mitsubishi brand after 475 days

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

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

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 color is produced by methyl group at 3’-position 2’-anilino-6’-diethylamino-3’- methylfluoran

17. Formation of different color fingermarks upon reaction with iodine Bro wn Brown color is 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 a) Sebaceous : b) Eccrine Develop fingermark of iodine fuming

19. i) Oddy brand : ii) Mitsubishi

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

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