On the morning of 20 October 2017, during a break between classes at Goyases School, a private school in Goiânia, Brazil, a 14-year-old student identified only as J.C.A.M. drew a .40-caliber Taurus PT100 pistol from his backpack and opened fire. The weapon belonged to his mother, who, like his father, was a military police officer. The attack killed two students, João Pedro Calembo and João Vitor Gomes, and injured four others; one injured girl became paraplegic as a result of her wounds.
According to the police investigation, the shooter reported having spent two months planning the attack, initially intending to kill only one classmate, but said he developed a desire to kill more people once the shooting began. In testimony to local police, he stated he had been obsessed with Adolf Hitler and cited the Columbine High School massacre and a Rio de Janeiro school shooting as inspirations. Investigators also found that the teenager had been the target of bullying from classmates.
Further casualties were prevented through the intervention of school coordinator Simone Maulaz Elteto, who entered the classroom when only the shooter and three fallen students remained, two of whom were believed dead at the time. Concerned that the shooter might reach other classrooms full of students or attempt suicide, Elteto persuaded him to accompany her to the school library. There, she calmed him until he dropped the weapon. Police officers then entered the library and arrested him. The shooter had reportedly intended to kill himself but was convinced not to by the teacher's intervention before his arrest.
In the aftermath, the Government of the State of Goiás declared three days of official mourning. On 21 October 2017, the Public Prosecutor's Office of the State of Goiás recommended provisional hospitalization of the perpetrator for 45 days; the judge on duty, Mônica Cézar Moreno Senhorello, accepted this request hours later. On 28 November 2017, the shooter was sentenced to three years of preventive detention, described as the maximum penalty available for minors under Brazilian law. He was released in May 2020.