Last Friday, a beautiful 12-year-old Paris girl named Lola failed to come home from middle school. Later that evening, her raped, strangled and mutilated body was found near her home in a suitcase.

The police quickly arrested a female suspect, ‘Dahbia B’, aged 24, whom they initially described as mentally ill. It then emerged that she was Algerian and was in an ‘irregular situation’ in France. And then that other Algerian migrants had also been arrested. As far as can be determined, on the day of the killing, ‘Dahbia B’ apparently waited for Lola to return home from school, seized her and took her to her sister’s apartment.

The further details are beyond sick. Lola appears to have been stripped naked and raped before she was butchered and killed. The police have been reticent but it’s reported Lola was literally eviscerated, during or after her killing. It’s reported that the numbers one and zero had been written on the girl’s feet. There are suspicions that one of the suspects attempted to sell the body.

This is not just another crime story in a city celebrated for them. It has rapidly become political. The left, terrified of offending its Islamist allies, has been mostly silent. But Éric Zemmour, the failed presidential candidate, has declared the killing to be yet another example of ‘Francocide’, a neologism he has created to describe the terrorisation of the French by jihadists and Islamist immigrants. Zemmour’s comment was quickly denounced by the interior minister, Gerald Darmanin, as ‘indecent.’

Emmanuel Macron belatedly recognised the murder – meeting Lola’s parents on Tuesday after a four-day gap. But the killing adds to what appears to be a growing sentiment that French authorities are losing their grip.

Social media accounts relay daily attacks and expose the incapacity of the police. To exacerbate the wound, Sunday was the second anniversary of the beheading by an Islamist of the high school teacher Samuel Paty.

None of this is optimal for Macron’s effort to reinvigorate his second presidential term. Much of the country is without fuel as a result of strikes at refineries. There have been violent acts at petrol stations as motorists struggle to buy fuel. Macron’s promised pension reform looks dead on arrival in the National Assembly. His threat to dissolve the Assembly and call new elections looks highly risky.

A sense of collapsing law and order might not be enough on its own to precipitate an existential political crisis but with everything else, it contributes to the impression of an administration that has lost authority in every dimension.

A demonstration has now been called for Thursday in front of the town hall in the 19th arrondissement where Lola lived. In a curious mirror of the situation on the other side of the Channel, authority seems to be draining away.