There have been innumerable films made turning children and teens into vessels to be feared rather than fawned over (2007's " Joshua " is a recent unsung treasure), and ever since the tragic 1999 events at Columbine there have been almost as many exploring the cause-and-effect?or lack of solid answers?behind school violence (among them, 2002's unforgettable " Elephant " and 2008's " The Life Before Her Eyes ").