Leonarde Keeler played himself in the classic noir movie, Call Northside 777 (1948), starring James Stewart and based on the real-life efforts of Chicago Times reporter James McGuire to exonerate Joe Majczek, a Chicago man who had spent eleven years in Joliet for the murder of a police officer during a delicatessen hold-up. The film was one of the first of its type to be shot in actual urban neighborhoods and the pivotal lie detector scene shows Keeler, a bit worn, but still masterful, calmly assessing the Majczek’s honesty.
In this clip we can see the pivotal lie detection scene, with Keeler playing himself.