Police came to know about the crime after Kuldeep Thakur's body was found dumped in a field in Mundaka on Friday morning. The minors were apprehended within hours.
"The two minors hired the cab from Najafgarh in west Delhi for Mundaka around 3.30 p.m. on Wednesday. On the way, a heated argument ensued between them and Kuldeep over some issue. After this, they fatally shot him in the head," Deputy Commissioner of Police Pushpendra Kumar told IANS.
"The minors dumped the body in a nearby secluded field and left the car at some other place before fleeing," the officer said.
Kuldeep, 51, was a resident of Khanpur in south Delhi.
The minors told the police that they shot Kuldeep when he abused them during the argument, Kumar said, adding that what exactly caused the argument was not yet clear.
The DCP said police did not find any previous criminal record of the minors.
"We are trying to find out how and from where the minors got the firearm used in the crime," he said.