The National Investigation Agency charge sheet in Margao serial blasts has indicated that a 20-year-old engineering student was the technical mind behind the incident in the coastal state on Diwali eve last year.
Dhananjay Ashtekar from Konkan belt of Maharashtra provided technical know-how and collected devices for preparing Improvised Explosive Devices (IED), which were successfully tested twice in two different states before October 16, 2009 when the blasts took place.
During the probe, the state police and NIA had zeroed in on Ashtekar and had found different electronic items required for assembling IEDs from his rented room.
Ashtekar is a student of DKTE Engineering College at Ichalkaranji and had downloaded the circuit diagram and later gave it for printing at a shop in Kolhapur.
The charge sheet, filed on May 17, mentions that Ashtekar, during July to September 2009, had contacted the owner of the shop, Rajesh Sonar, for preparation of printed circuit boards as per the diagram provided to him.
Sonar, had told NIA that he had prepared 18 printed circuit boards on the basis of four circuit diagrams provided by Ashtekar, one of the youngest accused in the case.
The investigations also revealed that Ashtekar had written 'On' and 'Off' directions on five IEDs in his own handwriting at the time of preparing IEDs.
The trail to make IEDs also led Ashtekar to Mumbai. The accused had purchased two transistors from a shop in south Mumbai's Lamington Road, the NIA said.
Another accused Vinay Talekar had also purchased five 9 volt batteries and two green colour insulation tapes for making IEDs from a shop in Goa's Ponda town.
Although NIA has filed the charge sheet, the agency is yet to get results of laboratory analysis of materials confiscated during the probe along with experts' opinion, which will be later submitted to the court.
The NIA, in its charge sheet, had accused 11 people attached to Sanatan Sanstha, a right wing organisation, of hatching conspiracy to carry out serial bomb blasts across the state.
Of the 11, four persons have been arrested, two died when the explosives accidently went off in their scooter and five are absconding.
The investigating agency had confiscated two IEDs which were defused at Sancoale, 20 kms away from Margao town.
The Bomb Disposal Squad (BDS) of Goa police defused these IEDs, which were planted in a pick up parked near the crowded spot.
Two accused, Vinayak Patil and Vinay Talekar, both in police custody now, had purchased second hand mobile sets from
a shop in Margao.
They also purchased two SIM cards with forged identity as they were aware that the police, during the investigation, will get to them through the mobile phones.
The investigators had also recovered remnants of IED, which was similar to IEDs used in both the incidents - Margao and Sancoale, from a roadside nullah on Margao-Ponda highway.
