According to police, one of the three other assailants, Azim, who are still at large in the case, had played a key role in the Karkardooma court firing by providing weapons to the juveniles with the purpose to train them.
Police said that the accused was apprehended on a tip off and has been identifies as Mohammad Vasim, a resident of Janta Majdoor Colony in Welcome area.
The agency claimed that the victim, Mahender Chand Ramola, who was into the business of ready-made garments, was dragged out of his office by four men and shot dead in the full public view on Monday night.
On Monday, Vasim and his three associates -- Azim, Sameer and Ashraf -- reached Ramola's office and eliminated him, it said.
"Recently, a raid was conducted and a gambling racket being run by Sameer and his partner, Sharif, was busted. 30 men were arrested for gambling in this raid, however, the duo managed to escape. The two accused suspected that the raid was conducted after Ramola tipped off the police. They developed enmity towards him and wanted revenge," a police officer said.