True crime, purposeful or exploitation?

This week both BBC and ITV are screening dramas about notorious murderers. The BBC are showing Rillington Place about John Christie whose crimes led to one man Timothy Evans being wrongly hanged for Christie's crimes. While ITV are showing In Plain Sight about notorious Scottish killer Peter Manuel. There has been a long history of the public being fascinated with horrible crimes. Do programmes like the ones above just feed that hunger or serve a greater purpose? The Christie crimes were already the subject of a film 10 Rillington Place starring Richard Attenbourgh and John Hurt as Christie and Evans, the film was based on a book by Ludovic Kennedy who wrote it as a anti death penalty piece in response to a Conservative MP's trying to pass a bill to bring back the death penalty. The death penalty in the UK is still no longer used because of such miscarriages such as those that happened to Timothy Evans. Drama about real crimes continue to be a staple of the TV schedules. whether their withstand the charge of exploitation may be depend  on what the programme is seeking to do.