Mansukh Hiran death case: Experts divided over key Diatom test

Mansuk Hiran`s body was found in the creek near Mumbra

As investigators hope to find a lead in the death of Thane businessman Mansuk Hiran through forensic tests, experts in Maharashtra have offered differing views on who should perform the crucial diatom test on the sternum bone extracted from a dead person. A diatom test throws light on if a person died due to drowning or was tossed into the water after being killed.

While the State Forensic Science Laboratory (SFSL) at Kalina says it is not them but a medical college which should do the test, some forensics experts say that the analysis is for academic purpose and may not be fully relied upon.

If blood grouping and swabs in sexual crimes, which can otherwise be tested in medical colleges, are sent to forensic labs in medico-legal cases, they why the diatom tests cannot be done by Forensic Science Laboratories, ask some forensic experts, stressing it is the practice in other states.

With an increase in the number of government / civic run medical colleges in the state, a Government Resolution (GR) dated July 1999 had allowed these colleges to conduct medico-legal autopsies, which is admissible as expert opinion under the Indian Evidence Act. However, there is no GR empowering these colleges to do tests like blood grouping, swab or diatom analysis.

The Criminal Procedure Code (CrPC), however, provides a list of experts, including those from central and state forensic labs who can testify their findings in a court.

Following the discovery of Hiran's body in Mumbra creek, the autopsy was conducted at Rajiv Gandhi Medical College, Kalwa, and his viscera and DNA samples and handkerchiefs that were allegedly stuffed into his mouth were sent to SFSL, Kalina for forensic analysis. While a piece of his sternum bone has been preserved during the autopsy, a senior FSL official said the medical college does the diatom test. When asked for the reason, the official preferred not to reply.

If the water sample collected from the spot, where a body is found, contains the same proportion of diatoms - algae-like unicelluar organisms - as the body, it indicates that the person drowned there. A negative result means the person was killed elsewhere.

An expert from a government medical college said the test is a part of forensic autopsy protocol. He said, "Even if the diatom test is positive, we must understand that there are thousands of diatoms, which can easily enter a human body, even days before death through the tap water at home and therefore diatom test cannot be considered as confirmatory evidence but it is a corroborative evidence."

Dr Rajesh Dere, Professor and Head of the department, Forensic Medicine and Toxicology, LTMG Medical college and Secretary Medico Legal Association of Maharashtra, said, "If the diatom test is performed by trained hands with due protocol, it may give a probable clue of antemortem drowning. All such tests usually have to be performed at forensic science laboratories and not at medical college."

Dr Shailesh Mohite, President of Medico Legal Association of Maharashtra, who is also the HOD of forensic medicine and toxicology at TN Medical College and BYL Nair hospital, feels the FSL should do the test as all other vital samples are sent there.

Dr Mohite added, "The percentage or frequency of species of diatom found in the drowning medium and in the deceased body, if found to be similar then one concludes that the person was alive, when he drowned. But in case, of body found in sea or creek (saline water), the diatom-algae type and the frequency will be different from that of routine diatom-alage found in tap water."

Police surgeon Dr S M Patil, who is also an advisor to the state on medico-legal cases, said, "It is a fact that there is no GR (government resolution) stating that medical colleges have to do the diatom test, but usually the practice is that the forensic surgeons who conduct the autopsy, would get the diatom test done at Grant Medical college. However, I am of the belief that such a crucial diatom test should be done only at the Forensic Science Laboratory, Kalina."

"The SFSL does not have a microbiologist (plant) to throw light on the diatom type. I have advised the FSL Director to get the vacancy filled. If a need arises, they can accept the sample and send it to Grant Medical college and JJ Group of hospitals through the police so that the procedure will have legal validity," said Dr Patil.

Dr Mukesh Yadav, Principal, Government Medical College, Banda, Uttar Pradesh and also Secretary of Indian Academic of Forensic Medicine, said, "We usually conduct diatom test, in cases where there is no direct evidence of drowning found during autopsy in the deceased chest and lungs, in such cases findings of diatom test is important. We send the sternum or any long bone found on the body for the diatom test to State Forensic Science Laboratory, Lucknow"

When asked about the debate about diatom test validity, Dr Yadav said, "Any scientific findings are debatable, but the dead bodies and evidence found on the body, never lie, which need to be corroborated by the investigating agency to ascertain the circumstances of death."

Dr Adarsh Kumar, Professor of Forensic Medicine and Toxicology, All India Institute of Medical Science, New Delhi.

The Diatom test has its own fallacy and is not used in every case of drowning. Diatom test is usually done in cases where a forensic surgeon is not able to lay hands to any direct evidence of drowning and only if he suspects that the probability of antemortem drowning cannot be ruled out. We usually send sternum or long bones for diatom analysis to State Forensic Science Laboratory, Karnal, Haryana, which is known for doing such diatom tests.

Dr Kusa Kumar Shaha, Professor of Forensic Medicine and Toxicology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, said, "It was during my postgraduate studies (between 1999 and 2001) at M.K.C.G Medical College, Odisha, we would do the diatom test within the forensic medicine department. However, in Tamil Nadu and Pondicherry, the diatom test is done only at the Forensic Science Laboratory (FSL) within the jurisdiction of the police station, where the body is fished out."

Dr Shaha, added, "Diatom test is a corroborative evidence and it is not a confirmatory evidence to ascertain the exact cause of death, for which the forensic surgeons, will have to consider the internal and external findings, family's statement and eyewitness account, if any to conclude the exact cause of death and to rule out any underlying pathological ailment."

What legal expert says

Rohini Salian, former Chief Public Prosecutor of Maharashtra said, "We must understand that the court would call for evidence and such evidence needs to be testified under the Indian Evidence Act (Section 45 - 55 expert opinion). Ideally, all forensic findings should be analysed and report submitted by authorised forensic scientists attached to State FSL as only they are empowered to give expert view under section 293 of CrPC. The report can be admitted as evidence, without examining such an expert, unless the court or the defence call him for the cross examination."

She added, "However, in case the test is done outside FSL, in a medical college, the moot question is admissibility of such a test report before the court and also the legal standing of such institution to conduct vital test on the basis of which the prosecution might build its entire case, and the same can fall flat during trial. Therefore, all such forensic analysis should only come from FSL."