Horrific School Shooting in Brazil: 12 Students Killed

Cell phone footage captured the dramatic scene after a gunman entered a school in Rio de Janeiro and started shooting.
The video may be disturbing to some people.
Authorities say the gunman shot and killed 12 children.
Witnesses say the shooter lined them up against a wall and shot them in the head at point-blank range as he shouted, "I'm going to kill you all!"
Officials say it's the worst school shooting in Brazil.
A police officer shot the gunman in the leg.
Then the officer said the gunman fell down some stairs and shot himself in the head.
At least 12 other students were hurt.
There's still no word on a motive or who the shooter was.