The man administering the polygraph test to convict Richard Conte was the inventor of the polygraph or lie detector machine, Leonarde Keeler. He played himself in the movie.
James P. McGuire served as a Technical Advisor on this film. He is the Chicago Times reporter who wrote the articles on which this film is based, and was the basis of the character played by James Stewart.
When McNeal tries to convince Zaleska to take the blame for the murder to exonerate Wiecek, Zaleska asks if he should name "Joe Doakes" as his partner. At the time, Joe Doakes was another name for "Joe Blow" or "John Doe."
The "roundhouse" where Frank Wiecek (Richard Conte) is kept at the Stateville prison was the only remaining panopticon still in use in the United States in the 1990s. It was closed in 2016, but the structure remains, due to its historical significance.
In 1946 James McGuire and Karin Walsh, the real-life people on whom Jimmy Stewart's and Lee J. Cobbs's characters were respectively based, won the prestigious Heywood Broun Award for excellence in investigative journalism for the Chicago Times for "stories helping free a man wrongly convicted of murder."