LLM Group 5 Criminal Law and Criminal Administration Forensic Science and Scientific Investigation of Crime 2024-25 Question Paper with Solutions

The serological sequence runs from sensitive to specific. For blood, the presumptive tests exploit the peroxidase activity of haemoglobin: the Kastle-Meyer phenolphthalein test, leucomalachite green, and luminol, which luminesces in darkness over traces of blood that have been washed away and is therefore the tool for a cleaned scene. These can exclude but cannot establish, because plant peroxidases and metal salts give false positives. Confirmation is by the microcrystal tests, Teichmann for haemin and Takayama for haemochromogen. Species is settled by the precipitin test using antiserum raised against human protein, now performed by gel diffusion or crossover electrophoresis. For semen the presumptive test is acid phosphatase, and confirmation is by microscopic identification of spermatozoa or by prostate specific antigen, which matters because it is detectable in a vasectomised or azoospermic man in whom no spermatozoa will be found. Saliva is identified by amylase.

India has no DNA statute. The DNA Technology (Use and Application) Regulation Bill, 2019 was withdrawn from the Lok Sabha in July 2023, so there is no DNA Regulatory Board, no statutory data bank and no compulsory accreditation of laboratories. The powers to take samples come from s.51 of the Bharatiya Nagarik Suraksha Sanhita, 2023, whose Explanation defines the examination of an arrested person to include blood, semen, swabs, sputum, sweat, hair and nail clippings by modern scientific techniques "including DNA profiling", from s.52 for a person arrested for rape and s.184 for the victim, and from the Criminal Procedure (Identification) Act, 2022, whose s.2(1)(b) includes biological samples and their analysis in "measurements", subject to the proviso to s.3 that a person arrested for an offence which is neither against a woman or a child nor punishable with seven years or more may not be obliged to give biological samples.

b) Forensic documents

Questioned document examination is the branch that establishes the authorship, authenticity and history of a document. Its subject matter is handwriting and signatures, alterations and additions, erasures and obliterations, indented impressions, ink and paper, typescript and printing, and security features on currency, stamps and identity documents.

Handwriting comparison proceeds on the premise that writing is a semi-automatic motor habit which is individual and which cannot be fully suppressed or fully imitated. The examiner compares class characteristics, which reflect the copybook system the writer was taught, and individual characteristics, which are personal: line quality, pen pressure and its variation, pen lifts, connecting strokes, proportions, slant, spacing, alignment, and the formation of particular letters. Adequate and contemporaneous standards are essential, and both requested specimens, written to dictation under observation, and collected specimens, written before the dispute arose, are needed, because a requested specimen alone can be deliberately distorted.

The law is specific. Section 39(1) of the Sakshya Adhiniyam makes expert opinion relevant on the identity of handwriting; s.41 makes relevant the opinion of a person acquainted with the handwriting of another; and s.72 empowers the Court itself to compare a disputed signature, writing or seal with one admitted or proved to be genuine. Section 349 of the Sanhita allows a Magistrate of the first class to order any person, including an accused, to give specimen signatures or handwriting, and a further proviso permits the order even against a person who has not been arrested, for reasons recorded in writing. That compulsion is constitutional because State of Bombay v. Kathi Kalu Oghad, AIR 1961 SC 1808 held that giving a specimen is a mechanical act furnishing material and not personal testimony, so Article 20(3) is not engaged.

The weight of the opinion is the contested part. In Magan Bihari Lal v. State of Punjab, (1977) 2 SCC 210, where a wagon of iron sheets was diverted by tampering with labels and the case rested on a handwriting expert, the Supreme Court held that expert opinion must be received with great caution, that it is unsafe to convict on it alone without substantial corroboration, and that this had almost become a rule of law.

c) Analysis of human bones

Skeletal analysis is the work of forensic anthropology and answers two sets of questions: who was this person, and what happened to them. Its material is bone recovered from a grave, a fire, a river, a mass disaster or a decomposed scene, where soft tissue no longer permits ordinary identification.

The first task is to establish that the material is bone, that it is human and not animal, and that it is of forensic rather than archaeological age, since the last determines whether there is any case at all.

Identification then rests on the four classical determinations. Sex is read most reliably from the pelvis, which is broad, with a wide sub-pubic angle and a large sciatic notch in the female, and secondarily from the skull, where the male has heavier brow ridges, a more prominent external occipital protuberance and a squarer mandible.

Identification may then be individualised by comparison with ante-mortem records: dental charts and restorations, which are highly individual, healed fractures and surgical implants, frontal sinus radiographs, which are individual, and DNA from the dense cortical bone of the femur or from tooth pulp. Where no records exist, facial reconstruction and craniofacial superimposition are used. Superimposition photographically or video-graphically overlays the skull on an ante-mortem photograph and tests whether the anatomical landmarks correspond, and its Indian standing was settled in Pattu Rajan v. State of Tamil Nadu, (2019) 4 SCC 771, where the Supreme Court accepted a superimposition result as part of the evidence, corroborated by other reliable testimony, while expressly acknowledging that the technique is not infallible.

The second set of questions concerns trauma. The bone records whether an injury was ante-mortem, showing healing; peri-mortem, occurring around the time of death, with the bone fracturing in a green and elastic state; or post-mortem, where the dry bone breaks with a different fracture pattern and colour. Sharp force, blunt force and projectile injuries leave distinguishable signatures, and the entry defect of a bullet in the skull is characteristically a clean internal bevel with external bevelling at the exit.

Conclusion. All three notes describe disciplines whose value is exactly as great as the record that accompanies the material. Forensic biology now individualises with a power no earlier technique approached, but Rahul shows that a two month gap in custody destroys it entirely. Questioned document examination remains the discipline in which the Supreme Court has been most openly divided about weight, and the Magan Bihari Lal and Murari Lal formulations are still not reconciled. Skeletal analysis produces ranges rather than facts, and the honest expression of the range, particularly in age estimation under s.94 of the Juvenile Justice Act, is the mark of a competent report.