Giri, who was a neighbour to Keshav's family, and one of his accomplices and driver, Ankit, have allegedly confessed to the crime during interrogation.
The four took 21-year-old Keshav to Bulandshehar district and shot him, disposing of the body in a nearby canal, hesaid.
Efforts are still on to recover the body, police said, adding that the two other accused are absconding.
A property dispute is said to be the reason behind the killing. The deceased's father Govind Pal Singh, a retired employee of the Irrigation Department, is currently working as a private contractor.