Chand was the officer who led the operation to crack the case and the terror module behind the parliament attack.
They cracked the case within a week and named four people, Mohammad Afzal, Shaukat Hussain Guru, S.A.R. Geelani and Navjot Sandhu, as having been behind the conspiracy. Police arrested the four from different places in the country.
While Afzal has been awarded the death sentence, Navjot Sandhu alias Afsan Guru was let off, and her husband Shaukat Hussain's death sentence was reduced to 10 years' imprisonment and he is now out of jail. Delhi University professor Geelani was also let off later.
Aggrawal, when asked, did not specifically say if sleeper cell numbers had increased in Delhi after the parliament attack.
"Their existence might have increased in the past years," he said.
