Road To Perdition - Poster Analyze

The clothes, the warehouse-lights and the machine gun give us a 'american prohibition' and 'mafia' feeling. The boy is standing behind one of the mans arms. That symbolizes that the man is the boy's protector, maybe father. This is also reinforced by the gun, which gives the man something threatening. 
The dark shadows in front of them and the light behind them symbolizes their journey from the known into the unknown.That also gets reinforced by the rain, which symbolizes a disaster or ending of something. The covered faces tell us that they are hiding from something in the darkness. The shadows and the light also symbolize evil and good and the light/good(the boy and his protector) is surrounded by the shadows/evil(mafia).
The different of levels of brightness around both and the gun in the mans hand shows us that he was a part of the mafia and did bad things and creates the expression of innocence in regard to the boy. The light in the darkness also symbolizes hope.
The headings reinforces the meaning that the man did bad things. The boy is carrying him out of the darkness(hell/perdition) into the light(heaven). The rain, which symbolizes angel's tears, and the form of the light, which looks like wings, reinforces this expression.
The poster tells us that this movie will include violence and gangster, but also will tell the story of the relationship between protector and boy and the dramatic story of 'saving the mans soul'.