This is a good, tense drama that builds up an interesting 'noir' story that includes some rather creative story elements. It has several strengths, but most of all it features three fine performances by Edward G. Robinson, Joan Bennett, and Dan Duryea. It's also easy to see Fritz Lang's skilled hand at work in the story-telling, mood, and pacing.
Robinson shows his skill and versatility in portraying a mild-mannered bank cashier who really wants nothing more than the chance to dabble in his painting, before getting caught up in a complicated situation. Bennett is quite effective as the opportunistic young woman who befriends him, and Dan Duryea adds his presence and ability to very good effect - Duryea had the knack of portraying this kind character as well as anyone. His appearance in any film-noir always seemed to make an average movie good and a good movie even better.
The story is developed carefully, as Robinson's character slowly begins to realize that he has gotten into a situation beyond his control. By the time that things come to a head, the tension is considerable. The ending is also rather resourceful, in being carefully written so as to satisfy the stringent requirements of the production code of the era while also ending the story in a way that seems appropriate and fitting to the tone of the movie as a whole.
All of this adds up to make "Scarlet Street" a fine movie that is well worth seeing, especially for fans of film-noir.