This document discusses indented writing and methods for deciphering it. Indented writing refers to depressions on paper created by writing pressure. Methods to reveal indented writing include using oblique light, pencil shading, and electrostatic detection apparatus (ESDA). ESDA is a non-destructive technique that uses static electricity to make indentations visible, even on papers up to 60 years old. It was used in a case to reveal an address from a bank robbery note that helped police arrest the suspect.

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 !