What strikes me about the placement of the backpack is that the house it was placed next to has no windows on that side of the house, and there is no view from the backyard due to the high fence, so the house the backpack was next to couldn't see what you were doing. The perp probably picked that location because of those reasons, although he still could have been seen by the house across the street on Andrew Way (maybe it's lights were out).
I wouldn't be surprised if the perp lives, or lived, in the area, or has some connection to it beyond looking for a victim. I lived in Jessica's neighborhood (a long time ago) and in Denver and Boulder, and those areas of Superior and Westminster are not areas you just wind up in, they are off the beaten path in a way. If you are travelling to Boulder from the central or east Denver metro area you take Hwy 36, and if you are going to Boulder from Golden or western Denver suburbs you take Foothills Hwy, both of which bypass Superior and that area of Westminster.