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"The process of DNA profiling starts with DNA being extracted from the crime stain and also from a sample taken from the suspect. In each case the DNA is cut into smaller lengths CRA-565-2022 by specific enzymes. The fragments produced are sorted according to size by a process of electrophoresis. This involves placing the fragments in a gel and drawing them electromagnetically along a track through the gel. The fragments with smaller molecular weight travel further than the heavier ones. The pattern thus created is transferred from the gel onto a membrane. Radioactive DNA probes, taken from elsewhere, which bind with the sequences of most interest in the sample DNA are then applied. After the excess of the DNA probe is washed off, an X-ray film is placed over the membrane to record the band pattern. This produces an auto radiograph which can be photographed. When the crime stain DNA and the sample DNA from the suspect have been run in separate tracks through the gel, the resultant auto-radiographs can be compared. The two DNA profiles can then be said either to match or not.""

6 DNA Profiling in Justice Delivery System, Central Forensic Science Laboratory, Directorate of Forensic Science, Kolkata (2007).

CRA-565-2022 than nuclear DNA, it can be used in the analysis of degraded samples. Similarly, the Y chromosome shows paternal inheritance and is employed to trace the male lineage and resolve DNA from males in sexual assault mixtures.

Only 0.1 % of DNA (about 3 million bases} differs from one person to another. Forensic DNA Scientists analyse only few variable regions to generate a DNA profile of an individual to compare with biological clue materials or control samples. ................................................ DNA Profiling Methodology DNA profile is generated from the body fluids, stains, and other biological specimen recovered from evidence and the results are compared with the results obtained from reference samples. Thus, a link among victim(s) and/or suspect(s) with one another or with crime scene can be established. DNA Profiling Is a complex process of analyses of some highly variable regions of DNA. The variable areas of DNA are termed Genetic Markers. The current genetic markers of choice for forensic purposes are Short Tandem Repeats (STRs). Analysis of a set of 15 STRs employing Automated DNA Sequencer gives a DNA Profile unique to an Individual (except monozygotic twin). Similarly, STRs present on Y chromosome (Y- STR) can also be used in sexual assault cases or determining paternal lineage. In cases of sexual assaults, Y-STRs are helpful in detection of male profile even in the presence of high level of female portion or in case of azoo11permic or vasectomized" male. Cases In which DNA had undergone 40 DNA profiling in Justice Delivery System, Central Forensic Science Laboratory, Directorate of Forensic Science, Kolkata (2007). environmental stress and biochemical degradation, min lSTRs can be used for over routine STR because of shorter amplicon size.

(18) In view of aforesaid legal position qua DNA profiling report and its probative value, the prosecution is duty bound to prove the guilt of the accused beyond reasonable doubt and burden is always upon the prosecution to lead evidence by taking all the precautions for proving DNA evidence. It is necessary for the prosecution as the entire process of collecting the blood samples for DNA profiling is controlled and done by the human agencies i.e. doctors and the investigating officers. Every step to preserve the sample from manipulation/contamination has to be proved, as absence of those steps may cause prejudice to the accused. The prosecution is required to put all the positive evidence CRA-565-2022 regarding the fact that all the precautions have been taken by the doctors as well as by the police officials regarding the preservation of the DNA samples. As held in the matter of Pattu Rajan (supra) DNA report is "an opinion" and its probative value varies from case to case. The science of DNA is at a developing stage, as such, it will be risky to solely rely upon the DNA report in absence of any substantive piece of evidence. (19) In the matter of Santa Singh v. State of Punjab7, the Supreme Court has held that if there exists a suspicious delay in sending the sealed parcel to the expert, the result is vitiated. (20) Similarly, in the matter of Amarjit Singh alias Babbu v. State of Punjab8, the Supreme Court has held that non-sealing of the revolver at the spot was a serious infirmity as the possibility of tampering could not be ruled out and observed in paragraph 7 as under: -

CRA-565-2022 4 does not show that any opportunity of hearing was granted to the victim before taking their blood samples for DNA test. The Medical Officer, namely, Dr. Amit Kumar Tiwari (PW-06) has also stated before the Court that the blood samples of the victim and her baby girl child, as per the identification forms i.e. Articles- 2 & 3, were handed over to the Constable of Police Station Ghumka. However, the said Constable has not been examined by the prosecution for the reasons best known to them. Further, though Articles- 1, 2 & 3 reflect that Investigating Officer, namely, Rajesh Kumar Sahu (PW-08) is one of the witness to the proceeding of collection of blood samples for DNA test, but in Para-17 of his cross-examination before the Court he has stated that the blood samples were not taken in his presence and he had not gone for conducting DNA profiling/test, but blood samples were produced before him in sealed condition. Further in Para-18 of his cross-examination he stated that he himself gone to Raipur for DNA test. The blood samples were said to have been seized by Rajesh Kumar Sahu (PW-08) on 12.02.2020 at about 12:10 PM on being produced by Constable No.519, namely, Surnedra Ramteke, but said seizure memo does not bear any sample seal, as per the requirement of Para-12 & 13 of the seizure memo (Ex.P/06). Thereafter, on 13.02.2020, the blood samples so collected/seized were CRA-565-2022 deposited with the FSL, Raipur by the Office of Superintendent of Police, Rajnandgaon by Ex.P/21 and receipt thereof is Ex.P/22. But, there is no document or any other material available on record to show that where the said blood samples were lying/kept for a period of one day i.e. from 12.02.2020 to 13.02.2020 (from collection till depositing with FSL, Raipur) and whether the samples were kept in safe/sealed condition during that period or not, as no documents/no copy of malkhana register has been produced to demonstrate safe custody of seized sample.