What is most disturbing about this film is not that school killing sprees like the one depicted actually happen, but that the truth is they are carried out by teenagers like Cal and Andre...normal kids with normal families. By using a hand held camera technique a la Blair Witch, Ben Coccio succeeds in bringing us into the lives of two friends who have some issues with high school, although we aren't ever told exactly what is behind those issues. They seem to be typical -a lot of people hate high school, so what? A part of you just doesn't believe they will ever carry out the very well thought out massacre on Zero Day. The surveillance camera scenes in the school during the shooting are made all the more powerful for that reason. You can't believe it's really happening, and that it's really happened. The hand held camera technique also creates the illusion that this is not a scripted movie, a brilliant idea given the subject matter.