Decipherment of indented writting
- 1. Presented By S.Shanmukhavalli BSC FS ‘B’ PIN no : 1914871494
- 2. INDENTED WRITING : ❖The depressed area on the surface of a document that was created by the pressure of writing or writing instrument.
- 3. METHODS OF DECIPHERING : 1. Photographically using oblique light : ❖ The oblique light fills the furrows of indented writing with shadows, that make writing visible.
- 4. 2. Pencil shading method : ❖ The pencil does not reach the depressions of writing. So the contrast is developed which makes the indentations more clear.
- 5. 3.ESDA : ❖It is a instrument used for revealing indentations or impressions on a paper. ❖It is a non-destructive method. ❖This can reveal indentations from 60 years old paper and up to 7 layers. ❖This method is based on charge transport model proposed by “RATHER SEWARD” in 1998 and 1999.
- 6. Working of EDSA : 1. Document humidification : Depends on relative humidity of environment Less than 60% - humidification is needed. More than 60% - humidification is not needed
- 7. 2: Document is placed over a porous earthen plate and covered by using Mylar sheet.
- 8. 3 : An electrically charged handheld Corona wand is waved over the document surface. ▪ An electrostatic image forms on imaging film.
- 9. 4: The black toner is then cascaded over the Mylar sheet that contain electrostatic image.
- 10. ▪The area containing the higher static electric charge retain greater portion of black toner resulting the indention marks visible.
- 11. CASE STUDY : ▪ Bank Robbery in London. ▪ This note was passed to the bank cashier. ▪ Once the recovered by police the note was submitted to the ESDA treatment .
- 12. ▪Impressions reveal an address . ▪Police arrested suspect at this address
- 13. Thank you !