The seven men from the underworld who killed investigative reporter Jyotirmoy Dey had no idea who he was when they shot him dead, police said on Monday.
Mumbai Police Joint Commissioner Himanshu Roy identified the man who fired the five bullets that killed Dey June 11 as Satish Kalia, a professional assassin who acted on the orders of underworld don Chhota Rajan.
Dey was a respected journalist who worked for Mid Day newspaper and specialised on the mafia. The daring afternoon murder triggered widespread protests, putting enormous strain on Mumbai Police.
But, even as they felled him, the killer gang of seven did not know who the victim was or why he was being killed, Roy quoted the arrested men as saying.
They panicked after realising that the victim was an ace journalist.
Roy said the gang members immediately split and dispersed to different parts of the country to escape the police dragnet.
The gang, Roy said, had carried out "a very professional job", having trailed Dey -- on the basis of the physical description given to them and the journalist's motorcycle registration number -- for days.
Six of the killers rode on three motorcycles while the seventh member was in a back-up van.
Roy told a news conference that Kalia, 34, used a Czech revolver and 25 "extremely deadly cartridges" that had been provided to him for the kill.
On June 11, it was Kalia who fired five bullets at Dey, one of which pierced his heart.
The first arrests were made in the temple town of Rameswaram in Tamil Nadu, where three from the killer gang were caught.
Later, the others were picked up from other places, including Mumbai.
Police said they had seized the killer weapon and 10 mobile telephones from the gang.
Roy said police were initially met with dead ends and disappointments.
"It was a very coordinated and copy book operation. A job very, very well done, very professionally done."