The juvenile had accidentally pushed the trigger of the pistol while he was showing off the weapon to his dance teacher at a dance academy at Sangam Vihar here on March 19, Deputy Commissioner of Police Chhaya Sharma said.
The bullet inflicted injury to the dance teacher, Nikhil.
Police had recovered the pistol, one live cartridge and one used cartridge from his possession.
A case was lodged on the statement of Nikhil and during the probe, the juvenile was apprehended.