Terror attack puts security front and centre - which suits Le Pen
It was what many French had dreaded. A terrorist attack just before presidential elections in which Marine Le Pen, the leader of the far-right Front National, is one of the leading candidates.
Many believed an attack in the run-up to the ballot would be a gift to Ms Le Pen, who has campaigned on a strong anti-immigration platform, linking it to security threats. It was hardly surprising then that Ms Le Pen seized on the killing of a police officer in a shootout on the Champs-Elysées in Paris on Thursday night to bolster her case, though the suspect is a French national who was being monitored by the security services.
Isil claimed responsibility for the attack and promised more.
A poll of voter intentions released just before the shooting showed centrist candidate Emmanuel Macron emerging as the frontrunner, with Ms Le Pen falling further behind him. But this has been one of the most unpredictable presidential election campaigns in French memory and few are willing to call it just yet.
French presidential elections comprise two rounds. Voters will cast their ballots in the first round tomorrow. The two candidates who glean the most votes will then face each other in a run-off election on May 7. In the past, tactical voting in the final round has prevented the far-right - in the form of Ms Le Pen's father, Jean-Marie, the founder of the Front National - from taking the presidency.
But there is an odd mood in France right now, with economic woes coupled with a string of terrorist attacks since 2015 contributing to a deep sense of pessimism about the future.
After the shocks of Brexit and Donald Trump's election, and with the gap between the four leading candidates very narrow, anything is possible.
Thursday's shooting was not the first terrorism-related incident to cast a shadow over the French election campaign. Earlier in the week, two men were arrested in the southern port city of Marseille on suspicion of preparing an "imminent violent attack" to disrupt the ballot. That news jangled nerves, feeding fears that Isil - which had already claimed multiple attacks in Paris in 2015 and last year's Bastille Day attack in Nice - might strike again.
Several commentators have argued that a Ms Le Pen victory would be welcomed by Isil - which includes many French nationals in its ranks - because it would set France, home to Europe's largest Muslim population, on a more confrontational path.
Nicolas Henin, a French journalist who was kidnapped by Isil in northern Syria and held for 10 months, has warned the terrorist group wants to see tensions rise inside France, particularly between French Muslims and the rest of the population.
While Ms Le Pen has sought to remake her father's Front National - long tainted by racism and bigotry - by focusing on her highly protectionist economic vision for France, in recent weeks she has stepped up her anti-immigration rhetoric. Always conflating immigration with security, she has vowed to tighten border controls and build more jails, and has accused the authorities of not doing enough to protect citizens from attacks like that on the Champs-Elysées on Thursday.
The fact it appears the suspect in this week's shooting was on a list of some 10,000 people considered to be potential threats to national security has already been pounced on by Ms Le Pen's supporters.
Since January 2015, terrorist attacks have claimed the lives of more than 230 across France, and the country remains in an official state of emergency.
Heavily armed soldiers are a constant presence in transport hubs and most cities. Newspapers and magazines regularly run features on how to cope in the new age of anxiety.
When news of Thursday's attack broke, Ms Le Pen was participating in a live TV debate with 10 other presidential candidates. She was quick to respond, arguing that France had failed to ensure security for its citizens: "I don't want our youth to get used to living with this danger. Naivety is over."
Hours before the French head to the polls - and with a record number of voters still undecided - the shooting in Paris has pushed the question of security, and who can provide it, front and centre of the campaign. That is likely to play in Ms Le Pen's favour but whether it tips the balance for her is another matter.
Her main challenger, Mr Macron, a former banker who resigned as economy minister last summer to establish his independent 'En Marche!' (Onwards!) political movement, may have been edging ahead in the polls earlier this week but his take on the issue of security is more nuanced than it is populist. How that may affect his chances remains to be seen.
Next week we will know which two candidates will face off in the second round.
Much can happen between then and May 7.