This was the last original episode broadcast on ABC.
This was the last 60 minute episode.
Ron Dean(detective #2) is in fact from Chicago. He would play a Chicago detective again in The Fugitive (1993).
At 19:46 Hooker gets out of the Cadillac and it's obvious that the car window is up. This despite an earlier statement that it was broken and couldn't be closed against the Chicago winter freeze.