The accused, identified as Manish, was arrested yesterday from Palam in southwest Delhi. A pistol, magazine and three live cartridges were recovered from his possession, DCP (Southwest) R A Sanjeev said.
Around three months ago, one Sunil Kumar Vats, who was a close friend of the accused was killed in Dwarka area. The murder was the result of an ongoing rivalry between two groups - one headed by Manish and the another by one Nikhil.
While the other accused involved in the case were arrested earlier, Manish was at large, police said.