French investigators are checking again for security flaws at Paris Charles de Gaulle airport after yesterday's EgyptAir crash, despite already stripping hundreds of employees of their security clearance since last year's jihadist attacks.
It is still far from clear whether the EgyptAir plane that crashed en route from Paris to Cairo was the victim of a terrorist attack or that any security lapse happened on French soil.
But security staff are taking no chances.
Following the attacks on Charlie Hebdo magazine and a Jewish supermarket in January 2015, the airport north of Paris imposed a zero-tolerance approach to staff, stripping more than 600 of its 86,000 employees of their security clearance.
Anyone with a criminal record lost their security pass, but the police authority that handled the review said 85 were suspected of having sympathies with radical Islamists.
Another 400 members of staff are still under investigation after being flagged as possible radicalisation cases, added a source close to the investigation.
With even one radicalised staff member with access to sensitive areas posing a potentially major threat, investigators are hunting for the slightest sign of radicalisation.
The refusal of a male employee to speak to or take orders from a woman, for example, is enough of a red flag to justify pulling his badge.
Investigators stress that they are not jumping to conclusions as to what caused yesterday's disaster in which all 66 passengers and crew were killed.
But they have questioned any ground staff who had the least contact or involvement with the plane.
The investigation requires close collaboration between the different services, including the air transport police (the GTA); the border police (the PAF) and the intelligence services.
They are striving to build a clear picture of what happened during the doomed plane's brief passage through Paris.
The Airbus A320 arrived in Paris from Cairo at 9:55 pm Wednesday. It took off again a little more than an hour later, at 11.09 pm.
Investigators are using everything at their disposal, including video surveillance, to identify passengers, crew, maintenance staff and baggage handlers who had contact with the plane.
