Shortly after the man in the hat, one of three terrorists who attacked Brussels' airport in March, was arrested, the federal prosecutors said they had made a discovery: the group that killed 32 people in Belgian had its sights initially set on France.
Mohamed Abrini - wanted by Belgian police who released photos of him pushing an airport cart in a dark bucket hat - had already been sought for his links to November's attacks around Paris that left 130 people dead. The Brussels explosions had been a rush job, prosecutors said, carried out by a group afraid of imminent capture.
French media cited sources close to the ensuing investigation saying Abrini claimed the intended target had been the Euro 2016 football championship, to be hosted in France from June 10-July 10. Liberation newspaper said that while the police and investigating magistrates were still trying to verify the information, it hadn't come as a surprise.
"It's not a scoop to learn that the terrorists wanted to attack during the Euro," Liberation cited a French police source as saying. "The security forces are always working on attack scenarios and countermeasures to respond to them."
Nevertheless, those measures have been heightened in the months since the Paris attacks, and French and football officials alike have sought to quell concerns that the championship could be marred by violence.
Seeking to uphold the resolute sentiment issued by French President Francois Hollande after the attacks - which partially targeted the Stade de France in Saint-Denis where he was watching a France-Germany match - politicians and organizers have insisted on keeping things as unchanged as possible, while ratcheting up the policing presence.
Euro 2016 organizers have said they would up the security budget by 15 per cent to 34 million euros (39 million dollars), for a tournament expected to draw 2.5 million spectators and bring 1 million foreign visitors to France.
UEFA plans to recruit at least 10,000 private security officers for the tournament and each of the 10 stadiums will have some 900 security agents on hand for each match. The government is working with the tournament organizers and private firms to make sure all the security forces are working together.
"Confronted with what will effectively be the most important coordinated public-private security operation ever organized in France and within the counter-terrorism context, it is necessary to be constructive," said Jean-Pierre Tripet, the head of private security umbrella union SNES, calling it an "exceptional challenge."
Particularly challenging are the fan zones, open-air areas where people can gather to watch the matches on big screens. Interior Minister Bernard Cazeneuve has promised video surveillance and increased security at the zones, where people will be barred from entering with large bags.
For the fan zones alone, where French media have said nearly 6 million people are expected to watch the matches, the security budget has doubled to 24 million euros.
With thousands of soldiers deployed to guard sensitive sites across France, as well as ongoing strikes and protests over a proposed set of labour reforms and migrant settlement operations that require a police present, some observers have raised concerns of widespread fatigue.
But Prime Minister Manuel Valls has said the government will seek a two-month extension on a post-attack state of emergency to cover the summer sporting event, and political commitment to the games has not flagged. Organizers for other major sporting events in France, including members of the Olympic 2024 bid committee, are looking to the tournament to be the standard bearer for managing security risk.
"There was never a question of turning back or cancelling," Hollande told organizers and members of the country's football association in March. "We know what happened, in Paris, in Saint-Denis. We were there. Many of the people gathered here today were there in the stadium... But the Euro 2016 must be a way of responding."