The knife assault at Paris police headquarters has been described as the most serious attack in France since the Bataclan. On Thursday 3 October, a police computer operator returned from lunch concealing a newly bought 30cm (12in) kitchen knife.
In a seven-minute spree he slashed, stabbed and killed three officers and a civilian worker – before himself being shot dead in the courtyard of the historic building.
It might seem curious to claim this as the worst since the Paris attacks of November 2015. What about the Nice lorry rampage which killed 86 in July 2016? What about the ghastly murder of elderly priest Jacques Hamel during morning Mass?
The difference, and the significance, is where it happened.
For the first time an attacker with apparent Islamist motivation struck from inside the system: not on the street, not in a church – but at the heart of the state apparatus.
Worse, it is now known that the perpetrator – 45-year-old Mickaël Harpon – gave out plenty of clues about his radicalisation. In 2015 he told colleagues the Charlie Hebdo attack had been “well done”.
And worst of all, no-one raised the alert – even though the very department in which he worked dealt with the detection and bringing to justice of… Islamist radicals.
The French can be excused for asking: if the anti-Islamist police intelligence branch cannot even spot a potential killer, how on Earth is anyone else expected to?
Quite clearly mistakes were made or, as Interior Minister Christophe Castaner puts it, “system malfunctions”.