Exploring Laboratory Analysis of Physical Evidence in Forensic Documents

Laboratory Analysis of Physical Evidence in Forensic Documents Section

When physical evidence is received by the laboratory section, various types of examinations are conducted to extract valuable information. The nature of evidence, corresponding examinations, and analytical information the laboratory can provide are summarized below:

Sl. No	Nature of Physical Evidence	Nature of Examination conducted	Type of Analytical information laboratory can provide
1.	Writings/initials / Signatures	Comparison with known standards.	Fix authorship with suspected individuals.
2.	Erasures (Mechanical and Chemical)	Examination under different light sources	Confirm existence of erasure, decipher original text.
3.	Obliterations	Examination under different light sources	Decipher obliterated writings.
4.	Indentations	Examination under ESDA, Poliview, VSC-4.	Develop indented writings.
5.	Tampered documents	Examination under different light sources	Detect tampering, potentially decipher original text.
6.	Type writings/Printed Matter	Comparison with known standards.	Determine if printed by same machine/type writer.
7.	Rubber stamp impressions / Metal seal impressions	Comparison with known standards.	Verify if impressions from the same stamp/seal.
8.	Paper	Comparison with standards.	Establish common source and relative age of docs.
9.	Ink	Examination under different light sources, FTIR, HPTLC	Establish ink origin consistency.
10.	Torn, mutilated and charred Documents	Examination under different light sources	Decipher original writings.
11.	Secret/Invisible Writings	Examination under different light sources, heat, etc.	Decipher invisible writings.
12.	Credit Cards/Identity cards	Examination under UV/IR/oblique light sources	Determine the authenticity and identity of cards.

By employing various techniques, the laboratory enhances its capability to extract valuable forensic information from diverse physical evidence.