This is an excerpt of BBC’s version of Crime and Punishment staring John Simm.
What FD does in scenes like this is he leads you round and round in an almost arbitrary fashion. It doesn’t matter whether the investigator laughs, cries or does a jig. The fact is that R is damned by his sin and it is struggling to ‘burst’ out of him – yet: “even men like you need a pin”. The investigator is the father confessor, the priest. Its a very 19th century idea of conscience. R wants to confess and needs spiritual guidance to do so but it is only through confession that his anguish will be assuaged – that he will be redeemed.
Nowadays we might believe that the guilty can live very easily with their guilt even given our century of psychoanalysis. Confessions are deployed in cop shows more as demonstrations for the audience that the correct conclusion has been reached. Evidence is the primary interest not confession. Confession is portrayed as the last act once the criminal has had overwhelming proof of guilt thrust in their face. Its icing on the cake for pure drama. Its not redemptive, indeed the criminal is often defiant in confession.