23AUse of firearms by police exercising powers of a prison officer

23A Use of firearms by police exercising powers of a prison officer (1) A police officer who is authorised under section 15 to exercise all or any of the powers of a prison officer is, when exercising those powers, subject to the following conditions on the use of firearms. (2) A police officer may discharge a firearm at a prisoner if— (a) the prisoner escapes or attempts to escape from custody; and (b) the police officer reasonably believes that discharging the firearm is the only practicable way to prevent the escape of the prisoner from custody. (3) A police officer may discharge a firearm at a person if the police officer reasonably believes that— (a) the person is aiding a prisoner in escaping or attempting to escape from custody; and (b) discharging the firearm is the only practicable way to prevent the escape of the prisoner from custody. (4) A police officer may discharge a firearm at a person if— (a) that person is using force or threatening force against— (i) a person in a prison; or (ii) an officer within the meaning of Part 5 (including the police officer carrying the firearm) acting in the execution of the officer's duties outside a prison; or (iii) a prisoner outside a prison; and (b) the police officer reasonably believes that discharging the firearm is the only practicable way to prevent that person causing death or serious injury. (5) Before discharging a firearm at a person, a police officer must— (a) if it is practicable to do so, give an oral warning to that person to the effect that the person will be shot at if that person does not stop escaping, attempting to escape, aiding an escape or attempted escape or using or threatening force (as the case may be); and (b) be satisfied that discharging a firearm at the person does not create an unnecessary risk to any other person. (6) A police officer may discharge a firearm that is a prescribed non-lethal firearm at a person if the police officer reasonably believes that discharging the firearm is the only practicable way— (a) to prevent, control or stop a riot in a prison; or (b) to prevent a serious threat to the security or good order of the prison.