Imagine Fritz Lang's M only instead of the very literal witch-hunt for the killer, you see the media in the form of judge, jury and executioner. Political parties and "honourable, decent citizens" explain their outlook on what should happen to the murderer of an 8 year old girl.
It is not interested in building tension in the march for justice but of investigating the social malaise in how we as a society have already come to a conclusion before a trial has even taken place. Should the death penalty even be considered in a case like this or should we be more humane to those who have been less than humane themselves? And as we are ever more influenced by the media surrounding us, how do we come to a considered opinion?