There appears to be very little police investigation in this programme. Lots of angst from the main player, buying alcohol and pouring it away, pouring wine and walking away, buying cocaine and snorting it, shouting and screaming about his tortured past but little real looking investigative police work. The usual stupid boss who seems frightened of losing his job pretty much all the time.
The first real bit of possible police work comes in episode 4. Don’t waste your time it’s not worth it