Memories of the Dunblane primary massacre will have come uncomfortably back to life this week with the stabbing of Luke Walmsley by a fellow pupil in a Lincolnshire school. Sadly for his parents, no amount of soul-searching can bring their son back.
What lessons can we learn? The first is to have a sense of proportion - thankfully, fatal stabbings in schools are extremely rare. We should not, therefore, indulge in panic measures whenever tragedy strikes. But schools will inevitably wish to take stock, just as parents will be anxious to know everything that can be done is being done to make sure their children are safe. Another lesson is that tragedy can strike anywhere: a school in rural Lincolnshire was as unlikely a setting for it as Dunblane.
There is no doubt that lessons for school security were learnt following Dunblane and the fatal stabbing of headteacher Philip Lawrence in London.
But, whatever improvements might be made by electronic detectors to confiscate weapons or the greater use of CCTV cameras, the real detection required is to spot children at risk - like Luke Walmsley's killer.