So I've found 5 red markers in various areas which seem to correspond to red markers in Chicago. However, I've only found 4 in Chicago so I guess I'm missing one. I found 2 in the Loop, 1 in the restaurant area, and 1 in underground chinatown.

Anybody have a hint where to find the fifth one?

Also, anybody know how to get into the Residential Complex? If I turn the camera right I can see a blue thing behind the wall...