Nitram

NITRAM is based on the life of Martin Bryant, leading up to the Port Arthur Massacre in 1996. it's a character study of an extremely mentally unwell young man, the story of Martin Bryant is a very unusual one and can be viewed in two different ways, you can either view Martin Bryant as having the emotional and intellectual immaturity of a child or you can view him as a cunning psychopath who is choosing to present himself this way as a means of manipulating those around him and attempting to avoid any consequences to his actions.  

Martin is presented in the film as being childlike and deeply immature, almost unaware of the consequences of his actions, unable to fit into society and connect with others his age, choosing instead to try and amuse the local children by setting off fireworks outside their school gates, at the beginning of the film Martin is portrayed as somewhat of an innocent, the only other adult he is able to form a relationship with is a wealthy heiress named Helen who plans to leave her his fortune, which is what helped fund the massacre.

Martin's story is a very unusual one, 
If you liked Snowtown chances are you might like this, 
that's the closest movie I would compare it to in terms of feel, 
It's an interesting look at a deeply disturbed mind.