A youth was shot on the Hemmingwell estate in Wellingborough as he rode his bicycle.
He was shot close to Nightingale Lane some time between 9pm and 9.40pm on Tuesday, September 29.
Officers carried out an extensive search of the area and were assisted by the police helicopter, with the investigation now passed over to detectives.
The injured youth was taken to hospital for treatment to injuries to his leg.
The shooting is the second incident involving youths in the town in two days after police were alerted to a group with a large weapon in Oakley Drive yesterday evening (Wednesday).
Police were called shortly after 5pm and after searching the area recovered a sword in Kiln Way.
Police are appealing for witnesses and information for both incidents.
Anyone with information should contact police on 101 or Crimestoppers anonymously on 0800 555111.