Additional Deputy Commissioner of Police, Devender Arya identified the deceased as Gulfam, 18, of Nand Nagri of east Delhi and the arrested as Karan and Sunny, also of the same area.
According to Gulfam's sister, he was taken out of the house by the juvenile, Karan and Sunny and then the juvenile stabbed Gulfam while the other two held him, police said.
Gulfam was taken to GTB Hospital where doctors declared him dead.
On Thursday, the trio hatched a plan to take revenge and stabbed him outside his house.
The juvenile was apprehended on Friday night and the knife used for the murder was recovered from his possession.