The victim, Om Prakash, was a field executive with an advertising agency.
The incident took place around 11.30 AM when Prakash went to the market in an auto to deposit a cheque in a bank.
"It seems that the assailants were following him because as soon as he got down from the auto, they shot at him from point-blank range. He sustained one bullet injury on his chest," said a police official.
When the auto driver tried to intervene, the assailants fired at him also, but the bullet missed him. The attackers then fled the spot, he said.
"The reason behind the murder seems to be personal enmity as the victim was not carrying any cash with him nor did the attackers tried to take anything away from him. But we are not ruling out robbery as the motive and are probing the case from all possible angles," said Deputy Commissioner of Police (North-West) Gnana Sambhandan.
Prakash is a resident of Sector-15 in Rohini.