In the scene where Murphy and his female partner are chasing Boddicker and the bad dudes who are riding in the truck, it shows them driving throught the streets of Detroit. Well, it isn't Detroit, it is Dallas, TX. You can tell by the downtown scene and the fact that Reunion Tower is in the background. That is a major feature of downtown DALLAS!
It's long been common knowledge that Robocop was filmed in downtown Dallas. One of the main police buildings in Dallas was the basis for the lower floors of the Omni Consumer Products building.