What are the main features of the usual crime/drama/thriller/comedy piece? Shootouts, blood, driving through the busy streets after the criminal or chasing him in the dark passages, foul language full of dirty words and sexual sayings... If there are no such things in the flick, it should be a senile "Ms Marple" piece of entertainment which cures insomnia all right. So, which class does this thing belong? Quite unexpectedly, to some other class. To the class of the movies where the actors create magic with the help of their talent. They don't need cheap tricks, sophisticated CGI, bloody shootouts, wisely choreographed fist-fights (though there is a cute one near the very end), etc. What they need is just one room where they can construct a detailed world of human emotions.
I won't come any further into the nuances, because this film gets right under the skin, fascinates and entertains.
A perfect job, which quite definitely deserves a few Oscars ("French Connection" is a pile of pulp if compared to this filmed story, in my very humble opinion) - 10 out of 10. Thank you for attention.