The teenager would be held in custody at an unnamed “facility that will take into account his youth and the care he needs”, lawyer Thierry Sagardoytho said.

Spanish teacher Agnes Lassalle, 52, was stabbed on Wednesday as she taught a class at Saint Thomas Aquinas middle and secondary school in southwestern seaside town of Saint-Jean-de-Luz.

Despite emergency medical treatment at the scene, she died of her injuries.

Lassalle had been a “good listener”, a “very kind teacher”, said Rudy, a middle school pupil who had a class with her last year.

Speaking at a press conference on Thursday, the Bayonne area prosecutor Jérôme Bourrier said that the 16-year-old boy was “intelligent and hard-working but shy and socially awkward and had been diagnosed with dyslexia when he was younger”.

On Friday, the boy’s lawyer told AFP that prosecutors charged him with murder.

During the press conference on Thursday, Bourrier said that the boy had told police that a “little voice” had told him to attack his teacher.

But he added that a psychiatric examination showed no sign of severe, Schizophrenia-style mental illness, although the boy had been receiving treatment for depression.

Bourrier said that the boy had used a kitchen knife that he had brought to school from his father’s home to stab Lassalle.

The boy was not previously know to police, or to social services. 

Schools around France held a minute’s silence on Thursday in memory of Agnès Lassalle.