The deceased had been identified as Colonel (Retd) Dilbagh Singh Ahlawat, police said.
Initial investigations revealed that there is park in front of the house of Col (Retd) Ahlawat in street number 12 in Jawahar Nagar. His neighbour Sukhbir Singh Phogat constructed a wall outside the park to which the retired Army personnel objected, police said.
Sarita, the wife of deceased was also present when the altercation took place last night, police said.
Phogat allegedly fired at the Colonel (Retd) following which he died, police said.
A case of murder has been registered against Phogat and some of his family members, police said, adding that no arrests had been made so far in this connection.