Although not always successful,"crack in the mirror" which is despised in France where the action takes place (it's one of the flaws of the movie: why locate the action there and make the viewer believe he is in Paris by using some words here and there :"Monsieur Le Président" "Monsieur Le Commissaire" "Monsieur Le Juge" and so on?)is in need of reassessment Richard Fleischer was always a brilliant thrillers maker .Many of his works are models of the genre,and during his whole career (if we except his dismal last decade ,roughly the years following "Solyent green" ):"the clay pigeon","trapped" and "follow me quietly" are early ;"compulsion" and "crack" are middle period ; "The Boston strangler" and " 10 Rillington Place are late (and perhaps his most brilliant achievements in the field).
I would not place "crack" as high as the others though.But this is a bizarre intriguing movie,which does not look like any other movie.Perhaps the two stories told in parallel (and played by the three same leads,which was not common at the time ) are there to hide the banal side of the subject (man/woman/lover triangle) ,but there are stunning flashes of inspiration:the mirrors which appear with the cast and credits;Lawyer Orson Welles entering the room where the old man was slain ,where the movie almost verges on the fantasy and horror genre -not unlike that scene in "follow me quietly " when the dummy comes alive" ;the same lawyer ,pleaing against the accused woman (and double crossing his colleague who was his wife's lover),his voice sounding like God's ;this sequence also mirrors the final of "compulsion" ,his precedent (and superior effort)where Welles plays a similar part.The fact that Bradford Dillman appears in both movies too adds to this strange similarity.
Juliette Greco is the only French artist of the whole movie (unless some -very- supporting actors count);she was primarily a Chanteuse,but oddly ,when she sings a love songs in front of the nuns/wardens ,she does not sound at all like she does when she sings in French;a question of language maybe;or maybe she was dubbed for the part of the working -class woman for I only recognize her voice when she portrays the bourgeois lady.