The media are calling for an overhaul of the gun licencing system which doesn't need to happen, all that needs to happen is that the rules need to be adhered to and in this case they weren't.
The government need to take as much flak for this as the police do, they have cut, cut, cut all our services and that includes D&C Police and the firearms licencing staff, they do not (or did not at the time) have nearly enough staff to carry out the work needed, this is purely the fault of the government.