When I first read Fredric Brown's 1948 novel, I was mesmerized. I have read it a few times since and have no intention of stopping-- it's really one of those forgotten classics of the hardboiled genre. Also being a Fellini fan, I have long been curious to see the film, Anita Ekberg's first starring role, (La Dolce Vita was two years later.) I know that Fellini was a pretty big fan of Brown-- at one point he planned to adapt his sci-fi novel What Mad Universe-- so I'm pretty sure he discovered Ekberg in this film.
Though I think the above reviewer was kind of harsh on Oswald and the cast-- especially Harry Townes, who understates the creepy obsessiveness of Doc Greene very well-- the fact is the movie falls short of the book by a considerable margin. I would put most of the blame on screenwriter Robert Blees, who had previously scripted the giant monster movie The Black Scorpion. But for all its faults (unfortunately, the ending is one of the things they botched) the film has its charms. Not only the cinematography but the music performed by Red Norvo captures the mood of the novel very well. And there are scenes that they actually get right. So I guess it's a love/hate thing for me.
Before I go, one last sidelight. Gypsy Rose Lee, who's featured in Mimi, was an exotic dancer in the forties and wrote one novel, The G-String Murders-- also about a killer who stalks strippers-- which was adapted as Lady of Burlesque, with Barbara Stanwyck.