In that actual murder case, two college students who happen to be geniuses decide that the rules don't apply to the superior intellect, and they murder some random child just for the experience, having planned the details out carefully. But since I am writing about this, apparently it was not careful enough.
All of the details of the murder case are pretty accurate, but there are fictional characters installed because this is more of a character study than a historically accurate account. These two fictional characters are Sid (Martin Milner) a college student and newspaper reporter, and his girlfriend Ruth (Diane Varsi).
Judd Steiner (Dean Stockwell) is a rough equivalent to Leopold. Arthur Straus (Bradford Dillman) is a rough equivalent to Loeb. This is still the 1950s, so the production code wouldn't allow you to just come out and say what is going on between the two of them, but the film does as good a job as it can of portraying Steiner as in love with Straus, although the film has Arthur/Artie as being the one who wants to indulge in all of the criminal behavior with Judd mainly going along so he can keep Artie close to him. In fact it was Leopold/Steiner who was the instigator of all of the crimes that led up to murder. Instead, Steiner is portrayed as a timid guy alienated from his family who would have probably just been a self involved loner with weird hobbies if not for the bad influence of Straus. In fact, I think Ruth is in this film just to insinuate that Steiner "liked" girls more than she is there as a girlfriend for the all American student journalist, Sid.
It's actually a pretty good look at what criminal investigators had to work with 100 years ago before there was DNA - identifying a typewriter from a ransom note, and being able to trace one pair of glasses out of thousands like it down to the person who owned them. As for interviews, before "you have the right to remain silent" was part of the police procedural vernacular, the smart investigator wants to keep the suspect talking - if he is guilty eventually he will trip himself up. Bright lights, billy clubs, and brutality are not required.
Although Orson Wells doesn't appear on screen until halfway through the film, he dominates the conclusion. His character, John Wilk, is based on Clarence Darrow who was probably the most famous defense attorney in the country during the early 1900s. He is faced with the difficult task of preventing two rich kids with every advantage who killed a child for the thrill of it all from going to the gallows.
