Les signes du mal

The most interesting parts of this series are the interrogation clips. Most of them using outdated and non scientific interrogation techniques.

A set of experts try to explain how every suspect in the series are psycopats, only based on transcripts and interrogations audio/video. Even if the experts sometimes agree that the suspects only have a degree of psycopathic behavior, the series miss an opposing view, with someone like professor Gisli Gudjonson and his work on false confessions and interrogations.

False confessions and interrogation methods would be another great tv series if you are more into documentaries based on facts than entertainment.