Death of Elisabeth Tenreiro: São Paulo school stabbing

On the morning of 27 March 2023, at around 07:20 local time, a 13-year-old male student enrolled at Thomazia Montoro State School in the Vila Sônia district of São Paulo, Brazil, entered his classroom armed with a knife and attacked teachers and fellow students. Witnesses reported that he first targeted his teacher, Elisabeth Tenreiro, before turning on other staff and pupils who attempted to intervene. Several students managed to flee the classroom and alert school security. Police arrived shortly afterward and apprehended the attacker within the school premises.

Elisabeth Tenreiro, a 71-year-old science teacher, was the primary victim of the attack. She sustained fatal injuries and later died at a nearby hospital. Five other individuals — three teachers and two students — were also injured in the attack, with at least one sustaining serious wounds but surviving.

Thomazia Montoro State School is a public secondary school in the western zone of São Paulo, serving students between the ages of 11 and 17. Prior to the attack, there had been no official reports of violent incidents at the school. According to early statements, the perpetrator had allegedly been involved in conflicts with classmates and had a documented history of behavioral issues. Reports also indicated he had a history of being bullied and had reportedly begun preparing the attack from around age 11.

Due to the attacker's age, his identity was not released to the public. Investigators examined whether the attack had been influenced by online extremist or violent content, noting that officials had observed a recent increase in similar incidents across Brazil. At the time of reporting, authorities stated that the specific motive for the attack remained under investigation.

The attack prompted widespread public debate in Brazil concerning school safety, bullying, and the spread of violent content online. Tarcísio de Freitas, the governor of São Paulo, announced measures intended to increase security in public schools, including the deployment of counselors and police officers. UNESCO issued a statement expressing regret over the killing and calling for the promotion of peace and nonviolence in schools.