A 23-year-old guman who killed 12 children in his former school in Rio de Janeiro acted alone, the head of city police's homicide division said Thursday.
Interviews with neighbors, family members and former classmates made it clear the shooter, Wellington Oliveira, "always acted alone," said homicide chief Felipe Ettore at a press conference.
"He is mentally ill, and had a psychotic episode that culminated with this tragedy that moved the entire country," said Ettore.
One week ago, Oliveira walked into the pastel green-and-yellow building where he'd attended elementary and junior high school, pulled two guns out of a backpack and started shooting the terrified children. Ten girls and two boys died; five children remains hospitalized, none of them in serious condition.
Some of Wellington's writings raised questions about his possible involvement with Muslim extremist groups _ among them a diary that discussed meetings with men named Abdul and Phillip and mentioned plans for an attack in Malaysia. Ettore discarded that line of inquiry, saying Abdul is the name of someone Oliveira knew from school.
Police on Thursday also arrested a third man for allegedly supplying one of the two guns used by Oliveira.
A judge ordered Manuel Freitas Louvise taken into custody after police traced the gun to him, according to a statement posted on a Brazilian court's Web site. Louvise confessed that he had sold a gun and ammunition to 23-year-old Wellington Oliveira, the statement said.
After he was arrested, Louvise told police he sold a .38 caliber gun to Oliveira in September 2010 for $760 in cash, also with 60 bullets and equipment to allow for quick reloading, Ettore said.
According to Ettore, Louvise, 57, said he was a grandfather of two children and regretted having sold the gun to Oliveira, who'd claimed he wanted a weapon for self-defence.
The shooter left two videos saying he had often felt humiliated and disrespected, and was planning an attack in the name of others who like him were bullied in schools.
A date has still not been set for classes to resume at the Tasso da Silveira public school, which was celebrating its 40th anniversary when the shooting happened.