Mohammed Moguchkov, 20, also made a “very marginal” reference to the Oct 7 attack by Hamas on Israel in the video before knifing the teacher to death at a school in Arras in northern France on Friday, the source added.
Moguchkov, a Russian from the mainly Muslim northern Caucasus region, was due to appear before an investigating magistrate later today to be charged.
The attack came almost three years to the day after a similar killing of a teacher near Paris, which shocked the public and triggered a massive security response.
France again raised its security level after Friday’s attack, deploying 7,000 troops.
Adding to the tension, the school in Arras was evacuated yesterday over a bomb threat, which proved to be a false alarm.
French president Emmanuel Macron has told ministers to “embody a state that is ruthless towards all those who harbour hate and terrorist ideologies”, a senior aide told reporters yesterday.
Macron later wrote that schools would remain a “bulwark” against extremism and “a sanctuary for our pupils and everyone who works there” in a post on X, formerly known as Twitter.
Macron’s office said he would attend the funeral of the victim, 57-year-old Dominique Bernard, on Thursday.
The murder has intensified nervousness in France, which has large Muslim and Jewish populations and has been on the alert for violence since Hamas’ attack on Israel.
Interior minister Gerald Darmanin said yesterday that 102 people had been arrested for antisemitic acts or expressing support for terrorism since the Oct 7 assault.
Bernard was killed almost three years to the day after teacher Samuel Paty was beheaded outside his school in a Paris suburb, on Oct 16, 2020.
The families of Paty’s killer and the suspected Arras assailant both hail from Russia’s North Caucasus region.
Moguchkov was born in the republic of Ingushetia and reportedly arrived in France aged five.
He was already on a French national register as a potential security threat and under surveillance by France’s domestic intelligence agency, the DGSI. His father, who was also on the list, was deported in 2018.
Macron has called on police to comb through their files of radicalised people who could be deported.
Darmanin said 193 such cases would be reexamined.
Macron has told Darmanin to focus especially on “young men between the ages of 16 and 25 from the Caucasus”, his aide said.