According to police, the boy called the cops to inform them about the incident after murdering the man, identified as Kuldeep, a native of Farrukhabad in Uttar Pradesh.
Kuldeep was shot dead last evening due to a rivalry between two families at his native place, the police said, adding the incident took place at a welding shop in Ghitorni area where the deceased worked as a contractor.
Senior police officials said there was a brawl between the two families after the murder at their native place but it was averted timely.
Police further said that to take revenge, when Kuldeep was at his native place recently, he got the juvenile beaten up by his friends after which the boy arranged a country-made pistol from his home town.
He said the accused himself called police and admitted to have committed the murder.
The police said that after the incident, Kuldeep's friends and family members in Farrukhabad had allegedly reached Rinku's place to take revenge but as the local police in UP was informed about the murder so the untoward incident was averted.