A teenager has been arrested on suspicion of attempted murder of a special constable.
Two special constables were out on patrol when they attempted to speak to a pair of males on Winchester Road, Feltham, at around 10.35pm on Thursday (July 16) night.
However, both males ran off from the volunteer officers, one on foot and the other on a bicycle.
They were chased down Exeter Road, where one of the youngsters was witnessed attempting to discard an item.
As an officer tried to detain the youth, a firearm was discharged in the direction of the policeman.
A 22-year-old male officer sustained minor injuries while he restrained the suspect but these were not caused by the firearm.
His 26-year old colleague was not injured.
A gun was recovered at the scene and is believed to be an air weapon. Forensic examination awaits.
A 15-year-old boy was arrested on suspicion of attempted murder and taken to a west London police station where he remained in custody on Friday afternoon (July 17).
Enquiries continue to trace the second individual.
Acting Chief Inspector Hannah Wheeler, from Richmond police, said: "The bravery and courage shown by our specials was extraordinary.
"They were out on patrol in a marked vehicle and saw two males acting suspiciously in a car park. When they went towards the males to speak to them they both ran off.
"The officers gave chase and as they detained one male he pulled a handgun out and pointed it at the officer and discharged shots.
"Thankfully none of the shots made contact with the officer and he managed to detain him despite the obvious risk to himself."
Special Constabulary volunteers give their time for free to work alongside full-time police officers.
Anyone with information should contact police via 101 or Crimestoppers anonymously on 0800 555 111.