Pedro Rosa da Conceição

Pedro Rosa da Conceição was a Brazilian spree killer who killed three people and wounded thirteen others in Rio das Pedras, Rio de Janeiro, Brazil, on April 22, 1904, before being arrested. He was then sent to a psychiatric hospital, where he later killed three more people: his cellmate Joaquim Alves Junior and an unnamed guard who attempted to calm him down during a fight in 1911, and an unnamed inmate in 1910. though this is unverified.

Rio das Pedras mass murder Rosa was epileptic and worked at the Estrada de Ferro Central. On April 22, 1904, he armed himself with a bayonet and went to a locomotive in the Belém station alongside a partner. However, as the train was speeding, Rosa pushed the partner out of the train. When the train arrived at Rio das Pedras station, Rosa left.

He then walked to the Dona Clara station, where his progenitor named Ambrosio Gomes lived. Intent on killing him, Rosa started beating Gomes injuring him. He then hit his stepmother, Maria da Conceição. Rosa fled to Rio das Pedras and started wandering around, injuring people past him. When he went back to Dona Clara station, he stabbed a corporal named João Teixeira de Oliveira to death. On the road he wounded Seraphina Maria. Rosa then killed farmer Fructuoso Goulart do Amaral and fled. One of his victims, Felicidade Ignacia de Salles, 15, died on April 27.

Murder of twelve people of a family A Noite, chronicling the crimes of Pedro Rosa, claimed that Rosa killed a family of twelve people, on an unspecified date and year.