Forensics in a fix

It’s been a week since the twin blasts shook Mumbai and the forensic labs of the country have not been able to give police the exact recipe of the explosive used. From ‘‘confirmed’’ reports on it being RDX and even PETN, now police say it was gelatin sticks. This is how the story on the explosives has changed.

August 26: It is PETN • WHO CONFIRMED IT: The Intelligence Bureau (IB) and the National Security Guard (NSG) • WHO BECOMES SUSPECT: Rich terrorist outfits Abu Nidal, the Palestinians and the Red Brigade. Rules out the hand of local outfits like SIMI.

• This one is being re-checked.

• Joint Commissioner (Crime) Satyapal Singh explains why. ‘‘High-grade explosives like PETN (Penta Erythritol Tetranitrate) and RDX fall in one category, so there may be a mistake.’’

• The Mumbai Police are waiting for the NSG report from Chandigarh, expected later this week.

This one made the investigators sit up. Never has RDX been used in the city after the serial blasts in 1993. There have, however, been seizures of about 5 kg in 2001 from Delhi and Ahmedabad. Located at Kalina, today the lab director Dr Rukhmani Krishnamurthy sits with fingers on her lips. This is after deputy CM Chhagan Bhujbal blasted her on Monday for making the lab report public.

When Express visited the director, she refused to even recognise the reporter. ‘‘I am not supposed to talk to the media,’’ she said. Two days after her men collected samples from the blast sites on August 27, Dr Krishnamurthi confirmed the use of RDX: ‘‘Our experts had collected samples from the remains and it is confirmed the use of RDX in both. It is, however, difficult to say what percentage.’’

After the arrest of the two accused, Hanif and Arshad on Friday, Mumbai Police are convinced it was gelatin sticks. They have a confession from the suspects on that. They also reported a seizure of 235 gelatin sticks, crackers, a machine and various other explosive material from Hanif’s house in Andheri.