Since we have SPD's crime scene sketch (p 145) and distance table (p 147), we can calculate the distances involved. First, the sketch itself:
http://i1061.photobucket.com/albums/t480/Cylinder1967/css.jpg
Distances recorded are in relation to two landmarks - Pillar A is the pillar supporting the patio on the northwest corner of 2861 Retreat View Circle. This is where the distance lines converge near the top of the sketch. Pillar B is that of the southwest corner of the adjacent townhose, 2851 RVC. This is where the distance lines converge near the bottom.
Looking at the photo of 2861 RVC, notice three things - first the pillar itself (below the dish), next the yellow marker for OM-4 (near the base of the white fence), and finally Pillar B (the pillar just next to the tree.)
http://i1061.photobucket.com/albums/t480/Cylinder1967/pillara.jpg
Looking at the distance table (p. 147) we see that the distance from Pillar A to OM-4 is 22 feet and the distance from Pillar B to OM-4 is 11 feet, 2 inches. (I believe that 39.10 is feet/inches and not a decimal notation with significant digits.)
Now we have established a base for a series of triangles from which to measure distance.
http://i1061.photobucket.com/albums/t480/Cylinder1967/csstriangle.jpg
Substituting the distances (after converting to inches) from the distance table (p. 147), and
solving the triangle, we find the following:
http://i1061.photobucket.com/albums/t480/Cylinder1967/triangle.jpg
Not quite useful yet, but we're getting there. Since I'm interested in the vertical distance (in the perspective of my diagram) from Pillar A to OM-6, I need to make a right triangle.
http://i1061.photobucket.com/albums/t480/Cylinder1967/rttriangle.jpg
Solving that right triangle, we find that the vertical distance from Pillar A to OM-6 (
segment d above) is 239 inches - right at 20 feet.
Since the townhomes are parallel to the sidewalk running between the them, we can also say that OM-6 is right at 20 feet down the sidewalk - not including the distance from the top of the T to the imaginary line connecting the north sides of the townhomes.