It's a mystery wrapped in an enigma and nestled in the blatantly obvious.
A man holding a gun on a French female soldier at Orly Airport shouted, "I am here to die in the name of Allah ... There will be deaths," before two of the soldier's comrades shot the attacker dead Saturday morning, a prosecutor told reporters.
Now French police are trying to solve this mystery.
Police questioned and then released relatives of a man shot dead at a Paris airport, as investigators sought clues on why he attacked an army patrol in an incident that has pushed security to the forefront of France's election campaign.
Paris prosecutor Francois Molins said late on Saturday that the man, named as 39-year-old Ziyed Ben Belgacem, had shouted he was there to "die for Allah" when he tried to seize a gun from a woman air force member on patrol at Orly airport.
He did announce it. That seems like a bit of a clue.
Belgacem, who had been in and out of prison for theft and drug offences according to judicial sources, was already on the authorities' radar. They said he became a radicalized Muslim when he served a prison term several years ago for drug-trafficking.
So the flics have figured out. It's the drugs.
"My son has never been a terrorist. He has never prayed: he drinks. And, under the influence of alcohol and cannabis, this is what happens," the father, whose name was not given, told Europe 1 radio.
This is exactly what every terrorist's father says. Funny coincidence that.
At least, so far, they're not trying to blame mental illness. As they have with nearly every other lone Muslim terrorist.
An autopsy showed the presence of cannabis and cocaine in Belgacem's body, as well as an alcohol blood level of 0.93 grams per liter, a judicial source said on Sunday.
Islam. It's a hell of a drug.
The legal limit for alcohol while driving in France is 0.5 g/l.
But what's the legal limit for murdering infidels?