Call Northside 777 is a 1948 documentary-style film noir directed by Henry Hathaway and starring James Stewart. The picture is based on the true story of a Chicago reporter who proved that a man in prison for murder was wrongly convicted 11 years before. The names of the real wrongly convicted men were Majczek and Marcinkiewicz for the murder of Chicago Traffic Police Officer William D. Lundy. Wikipedia
(McNeal is trying to get Zaleska to name his real partner in the crime and get a chance at parole)
P.J. McNeal: What have you got to lose? You're in for life now. C'mon, tell us the truth.
Tomek Zaleska: Sure, I could say I did it. Then maybe have a chance of getting out, like you say. And if I confessed, who would I name as my partner, Joe Doaks? I couldn't make it stick for one minute. That's the trouble with being innocent - you don't know what really happened.