New Delhi, Dec. 22 -- Over two weeks after a 52-year-old trader was shot dead in south Delhi's Aya Nagar, investigators have found that the assailants fired at least 80 bullets at him in what police believe was a carefully planned revenge killing, officers aware of the probe said on Friday.

The killing took place on November 30, when Ratan Ram was on his way to his dairy in Aya Nagar. Police said the attackers lay in wait for nearly half an hour, and opened fire the moment he arrived. The barrage of bullets continued for 5-20 minutes, leaving Ram dead on the spot. Forensic analysis has revealed that he was shot 69 times.

Police believe the murder is linked to an earlier killing involving Ram's son, Deepak. In May this year, Deepak alleg...