Does justice exists?

Judges are the people whom other fate is on their hand. They should not only use their brain to decide the case, but heart is needed to see the case clearer. Justice, is all we need. As Plato said,

" Knowledge without justice ought to be called cunning rather than wisdom. " ~Plato

I am a student of law, but i never ever want to be a judge. Can you imagine how does it feels when you have to decide something crucial on other people life? What if you made the wrong decision? What if you give the punishment to the innocent one but you let the wrong one to be free?

However, the thing that always comes on my mind, " does justice really exists? ". If it does, tell me where it is.