It came as a terrible shock to the tight-knit Jewish community in southwestern France.
Just days after nearby shootings of French soldiers of North African and Caribbean descent, a gunman pulled up on a motorcycle and opened fire on a rabbi, his two young sons and a little girl outside a Jewish school.
The incident led many people, including experts, to assume the perpetrator was a right-wing extremist opposed to immigration and minority groups, a viewpoint that has garnered popularity in Europe over recent decades and entered the mainstream political rhetoric of several countries.
The tone of this year's French presidential elections -- with strident statements on immigration and minority groups -- led to speculation that the political atmosphere had sparked the violence.
But analysts such as Marat Shterin, a sociologist and extremism expert at King’s College London, considered another scenario: that a seemingly contradictory form of radicalism -- Islamic militancy -- was behind the shootings.
“I find it quite remarkable that the two versions of the event were considered plausible, although ... the right-wing sort of theory was even more plausible in the eyes of most people," he says.
In retrospect, he adds, the theory of right-wing violence should not have been so prominent because its French advocates have legitimate outlets to circulate their views.
"You’ve got a very peculiar situation in which, in my view, right-wing violence is less likely in France but right-wing extremism is considered quite legitimate," says Shterin. "In my view, in countries where right-wing views are expressed openly, it’s less likely that they will be also expressed violently."
A common target
The shooting at the Jewish school was particularly troubling to so many people because three of its victims were young children. But the attack was also part of a pattern of strikes on Jewish targets in France.
According to Matthew Goodwin of the University of Nottingham, the shooter's specific ideological orientation -- assuming the killings were politically motivated -- may not have helped police target a suspect.
"One of the strange and also worrying factors about anti-Semitism is that it does cross the divide between politically-inspired extremists, such as those on the far right but also radical, violent Islamists who have particular grievances over issues around the Middle East and so on," he says.
The alleged shooter, Mohammed Merah, who was killed in a gun battle following a 30-hour standoff with police early Thursday, was a French citizen of Algerian descent who claimed to follow al-Qaida’s North African branch.
Authorities say he apparently targeted soldiers to retaliate for French Army activities in Islamic countries, perhaps choosing ethnic Arab paratroopers because he viewed them as traitors. Authorities think he may have gone to the Jewish school out of anger over Israeli policies.
Whatever the motives, his actions have triggered widespread mourning and solidarity among various ethnic and religious communities in France and elsewhere, and some soul-searching about how an open society can guard against the excesses of militant ideologies, regardless of their origins.