Nathan Leopold and Richard Loeb, the real killers, appear in archival footage sampled in the film. These shots, and most of the other footage in the film, were provided by the Chicago Historical Society.
In one night scene lit by car headlights, the "headlights" are actually just two halogen work lamps mounted on a C-stand.
The film was shot in two different blocks of time: first in October-November or 1990, then in August 1991. Craig Chester had to grow his hair back out after shaving it for the prison scenes, and then had his head shaved again when more prison scenes had to be filmed. The very first scenes shot was the kidnapping and the call from the phone booth.
The barber shaving Craig Chester in one scene is played by Jim Crawford, who did hair and makeup for the film. He is also the prison barber shaving the boys' heads later in the film.