One of the difficulties that Rajesh and Nupur Talwar, the dentist couple being tried for the murder of their daughter and manservant face as they mount their defence in what is a classic closed-door mystery, is that it is not merely enough for them to say they didn't commit the crimes. They must also point to who did.
The circumstances of the murder -- four people in a closed flat, two die, two live -- force the suggestion that the Talwars must know what might have happened. They were in the next room. Their explanation has been that they were asleep as the macabre events took place: it was summer, the air-conditioner was on, they didn't hear anything.
Throughout the trial, the Talwars have done their best to suggest plausible culprits: they have sought documents that hold the key to their suggestions. The special CBI court has told them in the past that they can call for additional evidence when their turn came in defence. On Monday, that time had come.
The documents the Talwars seek are those that purportedly make clear who killed Hemraj and Aarushi. In an application filed on Monday, they sought reports of the narco analysis and brain-mapping tests done on the three servants, and former accused, by FSL Bangalore.
A day after the tests were conducted on Krishna, one of the servants, investigators recovered a khukri that was, at one time, considered the weapon that caused the fatal blunt injuries on Aarushi and Hemraj.
At least two U.P. policemen, appearing as prosecution witnesses, have testified that the servants had admitted their involvement in the murders. But this line of investigation was abandoned, and more than two years into the investigation, the murder weapon transformed itself from a Krishna's kukhri, to Rajesh Talwar's golf club.
The chain of custody of the golf club has been established as compromised during the trial: it had been sent to forensic labs, but seals from the labs had long been removed, in the office of the investigating officer, according to evidence on record.
The Talwars want to bring in their own forensic expert to give his opinion on the golf clubs. They have sought the court's permission to allow him to inspect them.
The trial court is well within its powers to call in all the evidence the Talwars seek. Evidence that gives them the chance to answer that question: 'If you didn't do it, who did?' They will make their arguments on Wednesday.
Aarushi Trial: Talwars in the dock