Near the middle of the episode, an elevated train is seen rushing by in the background. This train is neither the "Peoplemover", which runs a loop in downtown Detroit, nor is it an Amtrak train, which runs at ground level through the city.
Members of the Detroit Police and Fire Departments are required to live within the city limits of Detroit. A uniform would never brag to a detective about living in Ferndale, which is a suburb of Detroit. There are several scattered police neighborhoods in Detroit.
When James Burke's record is pulled up on the computer, the Michigan State Police address in Detroit shows a zip code starting with "1." All Detroit zip codes start with "48." In fact, when asking for an address in Detroit, it's common to give just the last three digits of the zip, since it always starts with "48."