The 32-year-old aspiring techie-turned-terrorist, Ariz Khan, had played a key role in all. He helped make the bombs that were planted at the sites and cost the lives of 165 people.
Apart from his involvement in the serial bombings, Ariz Khan was among the four terrorists present at Delhi's Batla House where an encounter took place on 19 September 2008. The police team had killed two terrorists of Indian Mujahideen who were present there. Inspector Mohan Chand Sharma, who led the police action, was killed during the operation.
Here's a recap of the major bombings cops say Ariz Khan had been involved in:
UP Court Blasts, November 2007
The simultaneous blasts that shook the courts of Lucknow, Varanasi and Faizabad, had been triggered by a case of assault at the sessions court of Lucknow. Some lawyers had got together and beaten up three men, who were terrorists of Jaish-e-Mohammed. To teach the lawyers a lesson, the Indian Mujahideen planned to set off explosives at three courts of the state. Seven Improvised Explosive Devices or IEDs were put together by the team and planted at the court premises on November 23. Ariz Khan was part of the team that placed 3 explosive devices at Lucknow courthouse premises. Five minutes before the bombs were to go off, they sent an e-mail to media houses accepting responsibility.
The string of synchronised blasts that took place in Jaipur in May 2008 was among the deadliest attacks carried out by the Indian Mujahideen. Of the 10 IEDs that were planted, nine went off, killing 63 people and injuring 216. Ariz Khan, the police sad, had worked closely with the Bhatkal brothers - Yasin and Riyaz who headed the group. He and his associates, the police said, had collected the explosives, put together the IEDs.
Blasts in Ahmedabad, July 2008
A string of 21 bombs had gone off in Ahmedabad, on July 26, 2008 in a span of a few hours, killing 57 people and injuring 158. The maximum number of people had died when one of the bombs exploded at a trauma centre. The next day, two cars, packed with explosives, and 18 undetonated bombs were discovered across Surat. Ariz Khan and his other associates were in the city 15 days ahead of the blasts to conduct a recce, the police said. They then went to Delhi but were back in the city three days before the blasts to plant the bombs.
Delhi Serial Blasts, September 2008
The police said Ariz Khan had played a pivotal role in Delhi serial blasts of September 13, 2008. The five bombs they planted bombs tore through three of the busiest commercial areas of the national capital -- Karol Bagh, Connaught Place and Greater Kailash, killing nearly 30 people and injuring more than 100.
Ariz Khan and his associates, the police said, had brought the explosives from Udupi, Karnataka and put together the bombs in Delhi. The other material that went into the making -- alarm clocks, 9 volt batteries, light bulbs, circuit wires, digital multimeter, pressure cooker and pencil cells were bought from Lajpat Market.
After conducting a recce, Ariz Khan, with key associate Atif Ameen, had planted IEDs at the M Block Market of south Delhi's posh Greater Kailash, the police said.