Police arrested a teen identified as for allegedly helping plan the school attack in Sao Paulo on March 13 that left 10 dead, the local police has said.
The 17-year-old man was arrested at his home in Suzano, metropolitan Sao Paulo, and was then transferred into custody of judicial facilities because he is a minor, according to Sao Paulo's Civil Police.
The adolescent made voluntary statements before the court on Thursday but was released after he denied taking part in the attack.
Police investigation, however, uncovered evidence showing his link to the attackers. They discovered messages on his cell phone with the two attackers, reports Xinhua.
Among the evidence presented by the police was a statement by a teacher, who said earlier this month the young man wrote in a classroom exercise that his biggest dream was committing a school shooting.
The attack occurred when two young men, aged 25 and 17, entered a public school in Suzano, and began firing indiscriminately. The two shooters then killed themselves at the scene.
Three students remain hospitalised, with one in serious condition. Police are still investigating the reason for the shooting.