Reasonable doubt can settle a murder case in favour of the defence, but the accused always carry the another subtle yet heavy burden: that of having to provide a reasonable alternative hypothesis. If they didn't do it, who possibly did?
The one piece of evidence in the Aarushi-Hemraj murder trial that opens up the possibility of someone other than Dr Rajesh and Nupur Talwar having committed the murders was the focal point of Wednesday's proceedings at the Ghaziabad special court. It is a pillow cover recovered from the home of one of the initial suspects in the case, Krishna, an assistant at Dr Talwar's dental clinic who lived in the same NOIDA housing complex as the Talwars.
The purple pillow cover recovered from Krishna's bed, a few houses away, had blood on it. When the item was sent to the Centre for DNA Fingerprinting and Diagnostics (CDFD) in Hyderabad for testing, the renowned lab reported that the DNA generated from it matched that of one of the victims: Hemraj.
How could Hemraj's blood have reached Krishna's bed unless he was involved in the killing? This is the question that the Talwar's placed before the Allahabad High court in early 2011, as they contested the summons issued by a Ghaziabad court to stand trial for their daughter and manservant.
The CDFD report had come in 2008. The evidence was as direct as it gets. Two teams of the CBI had over two and a half years to look at it, but neither saw it. The Talwars did, as they mounted their defence, and this is where a bizarre and disturbing story begins.
The CBI had someone rushed to Hyderabad. In a matter of seven days in March 2011, shortly after Talwars pointed out the evidence that implicated Krishna, a crucial change was made. There were two similar pieces of evidence that went for testing: one a pillow and a pillow cover recovered from Hemraj's room in the Talwar's flat; the other, just a pillow cover seized from Krishna's home. The CDFD report said blood was found on both pillow covers, but that Hemraj's DNA was generated from Krishna's bedding. This was now changed with a simple swap: years after it was submitted, the CDFD said that there had been a typographical error in its report. The results for tests on Krishna's pillow cover were to be read as those for Hemraj's pillow cover, and vice versa. The new, neat, formulation was this: Hemraj's bedding contained his DNA; Krishna's pillow cover contained blood, but it wasn't clear whose.
The prosecution witness testifying on Wednesday was S.P.R Prasad, one of the CDFD DNA examiners. He admitted that there his lab had committed an error, and then explained how it was corrected. It began with a letter from the CBI written in Hyderabad asking very specifically whether there were typographical errors in the reports of the two samples in question. After a process that lasted just five working days, and from all accounts no verification of actual material, the CDFD wrote back to the CBI saying that the results for Krishna's pillow cover should be read as those for items recovered from Hemraj's room.
This simple swap took away the basis for the alternative hypothesis that the defence must try and provide. Serious questions remain on how the swap took place:
* Why wasn't the "error" spotted before the Talwars pointed out the evidence implicating Krishna?
* The CDFD is fairly careful with its typing. There is evidence of this in its communication with the CBI. A January 2010 letter to the CBI points out, for instance, that the agency has gotten its exhibits mixed up, and helpfully corrects this error.
* The process followed to make the "correction" as described by Prasad is sketchy. There is nothing on record to show exactly how the CBI's query was dealt with by the CDFD. In smaller matters than life and death, mistakes in a DNA report must go to a committee for correction/action.
One other question cropped up on Wednesday. And this was about accountability. One of the scientists brought down from Hyderabad, Prasad's senior colleague Dr Madhusudan Reddy—the author of the clarification to the CBI—was also to testify. Except that he had never been listed as a witness by the CBI's legal team, led by the R.K. Saini.
The trial judge would have none of this: you cannot just walk into court and give testimony. He asked the prosecution to make the appropriate request to the court. The prosecution's response was to drop Dr Reddy as a witness.
Dr Reddy is Hyderabad-based. His non-appearance may or may not hurt the prosecution, but it was a waste of taxpayer's money. You and I pay for the sloppiness of legal counsels representing the state. This, of course, has never been a concern at the CBI.
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The missing post-mortem doctor
Did the Talwars place Aarushi's phone in the park?
How are the Talwars paying their bills?
A dubious witness and the strange case of the word 'rape'