I think (because I haven't played recently) that frosty told you where to go at the beginning of the run. IIRC the four places where the Johnsons showed up are an alley at the lower left edge of Redmod, on the second floor of the squat in the upper left edge of Redmond, the parking lost at the right corner of Northside and the first floor of Royale apartments in Downtown.

Many thanks!