development of latent fingermarks on thermal paper: preliminary investigation into use of iodine...
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Development of latent fingermarks on Development of latent fingermarks on thermal paper: Preliminary investigation thermal paper: Preliminary investigation into use of iodine fuminginto use of iodine fuming
Persent by
Pol.capt Nanthakarn Taljinda
Om Prakash Jasuja ; Gagandeep Singh . F 19orensic Science International, Volume
- N NN2 , 1 , 1 1 1 6 , 2 0 2009ember
IntroductionIntroduction
Thermal Thermal paperpaper- Its extensive use in the Its extensive use in the
modern day lifemodern day life
- Introduced by National Introduced by National Cash Register Company in Cash Register Company in 19681968
- Reaction Between leuco Reaction Between leuco dyes and co-reactantsdyes and co-reactants
Introduction
- - Heat Heat blackblack- Substituted Substituted fluoran fluoran different colorsdifferent colors
- Reaction - Reaction involves openinginvolves opening ring structurering structure
Various Various techniques to techniques to developdevelop
- Ninhydrin- Ninhydrin
-1,8-diazafluoren-9-one 1,8-diazafluoren-9-one ((DFODFO))
- dimethyllaminocinnamaldimethyllaminocinnamaldehyde dehyde ((DMACDMAC))
- Metallo-porphyrin - Metallo-porphyrin compound compound [[((TPPTPP))SnSn((OHOH))22]]
Introduction
Iodine fumingIodine fuming
Simple method, is inexpensive, Simple method, is inexpensive, fast and reversiblefast and reversible
Non-destructive paper or any Non-destructive paper or any writing on the paperwriting on the paper
Developed fresh as well as age Developed fresh as well as age latent fingermarkslatent fingermarks
AdvantagAdvantages :es :
DisadvaDisadva
ntages :ntages :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 fumingIodine fuming
Material and methodMaterial and method
Type of thermal Type of thermal paperspapers
Mitsubishi fax Mitsubishi fax paperpaper
Oddy fax paperOddy fax paper
D.P. Print D.P. Print paperpaper
ATM paper ATM paper receiptsreceipts
10 donors their finger gentle rubbing of the cheeks or forehead (sebaceous)
Material and methodMaterial and method
10 Donors their wash hands(eccrine) Donors were placed
on thermal papers
Donors
UV : 5-10 min
Kept in dark
photophotographgraph
photophotographgraph
Results and Results and discussionsdiscussions
Permanency is dependent upon the type of thermal papersMitsubishi and Oddy fax paper > Mitsubishi and Oddy fax paper > ATM paper and D.P. print paperATM paper and D.P. print paper
Results and Results and discussionsdiscussions
MitsubishiMitsubishi brandbrand after after 475 days475 days
Different types of thermal paper resulted in different colored fingermarkMitsubishi , Oddy, ATM receipts Mitsubishi , Oddy, ATM receipts green / greenish blackgreen / greenish black
D.P. print paper black / brown / yellowish
Results and Results and discussionsdiscussions
Mechanism of the fingermark development
Iodine is electron-accepting
leuco dye
open lactone ring color formation
oxidize
Mechanism of the fingermark development
O
O
O
NH
Et2N Me
I
O
OH
O
NH
Et2N Me
Colorless Form Colored FormO
O
O
NH
Et2N Me
I
O
OH
O
NH
Et2N Me
H
I2 2I
Develop fingermark of iodine fuming
UV:Dark
Formation of different color fingermarks upon reaction with iodine
GreeGreenn
O
O
O
NH C4H9
Green color is produced by presence of two tertiary amino group at 2’ or 6’ positions
2’-n-butylamino-6’-diethylaminofluoran
Formation of different color fingermarks upon reaction with iodine
BlackBlack
O
O
O
NH
Et2N Me
Black color is produced by methyl group at 3’-position
2’-anilino-6’-diethylamino-3’-methylfluoran
Formation of different color fingermarks upon reaction with iodine
BroBrownwn
Brown color is produced by replacement of amino group at 2’-position with azomethine group e.g. 6’-diethylamino-2’-ethyl-lidenaminofluoran
Develop fingermark of iodine fuming
a ) Sebaceous : b) Eccrine
Develop fingermark of iodine fuming
Develop fingermark of iodine fuming
i ) Oddy brand : ii ) Mitsubishi
Develop fingermark
Left:
by iodine fuming
ATM paper
Right:
by DFO
Develop fingermark of iodine fuming
1 year old
Conclusion
- Developed fresh as well as - Developed fresh as well as age latent fingermarksage latent fingermarks- No BackgroundNo Background- PermanentPermanent- Clear and legible Clear and legible fingermarksfingermarks- Oxidation of leuco dyesOxidation of leuco dyes- Various colorVarious color- It is sensitivity sebaceous marks
