Engrenages (in the UK it is called 'Spiral' - but literally it means 'gear') is a TV series about how the French police & juridical system work. The main characters are: Captain Laure Berthaud, Judge Roban, Prosecutor Clément, Maître Karlsson, and police officers Gilou and Tintin.
I bought a box-set which consists of season 1 & 2, which I finished watching last night. I think it was very good, although when I first started watching it, I thought the colour was rather pale. Not sure if it's the quality of the DVD (from BBC) or the movie had been made that way. In each season, there is one main case, with new cases in each episode. In the first season, they investigate the murder of a Romanian woman - which leads them to a high politician, a bit like 'State of Play'. In the second season, it's about a drug ring.
The main characters have their own problems, except Judge Roban - who is very clever - and Tintin.