Tiago Rocha, 26, was arrested after admitting the murder of 39 people in the city of Goiania.
He murdered young women, prostitutes and homeless people by shooting them from a motorcycle.
KILLER ADMITS TO MURDERING 39 PEOPLE
His youngest victim was just 14-years-old.
Rocha claims he committed the horrific crimes were due to the trauma of being sexually abused as a child.
He was caught after an attempt to kill his 40th victim failed, and he was later identified by the victim.
According to reports, Rocha has already tried to commit suicide in prison by slashing his wrists with a light bulb, but more disturbingly he asked workers if he could kill again.
Brazilian police chief Eduardo Prado said: “He asked whether he would face trial if he killed someone else in custody.
“He still wants to kill. His attitude is very strange.”
Mr Prado continued: “We’re monitoring him constantly. He doesn’t love himself and he’s already attempted suicide.
“He constantly asks for dental floss to take with him when I’m with him. When you ask him if it’s so he can kill himself he just laughs sarcastically.”