Two police officers have been disciplined after leaving their guns locked in the glove compartment of their car in Northern Ireland.
Later a shot was accidentally fired through the floor of the vehicle in a public car park outside Hydebank Young Offenders' Centre in Belfast as a policeman performed a safety check, the Police Ombudsman said.
The PSNI took an hour-and-a-half to inform Michael Maguire's office and by that time the officers involved were returning to Fermanagh in their car.
"While it remains necessary for police officers in Northern Ireland to be armed, there comes with that a responsibility to ensure that weapons are handled in a safe and secure manner to minimise any risk to officers, their colleagues and members of the public," Dr Maguire said.
Three officers were disciplined after failings were identified by the ombudsman's investigation. One was penalised for the negligent discharge of his firearm, he and a colleague were disciplined for leaving their guns in the car, and a more senior officer was reprimanded for failing to follow proper procedures afterwards such as securing the scene, car and weapon.
The policemen travelled to Hydebank from Fermanagh and left their guns locked in the vehicle's glove compartment while in the prison. One officer said another colleague had previously questioned the security of storage facilities at Hydebank.
The centre had a clear policy for securing police firearms during visits, involving weapons being checked in and out and locked in an armoury box, the ombudsman said.
The gun discharge happened as the officer undertook a safety check on the weapon after returning to the vehicle following the visit to Hydebank. The officer admitted he failed to properly follow safety procedures when checking the gun.
The ombudsman said it was fortunate no one was killed or seriously injured. He criticised the officers' decision to leave their weapons in the car and expressed concern about a delay in his office being informed by police that a bullet had been fired.
"Proper procedures were not followed. The scene, car and weapon were not secured, and the officers involved were allowed to leave the scene, contravening procedures to ensure that all discharges of police firearms in Northern Ireland are subject to full independent investigation by my office," he said.