In the graphic I made (see below) please note the similarity of the roof-lines. IMHO, the perpetrator(s) was a stranger to the victim; the backpack was a red-herring; the perpetrator(s) feels comfortable loitering in a vehicle parked on the side of a street where there are no windows overlooking the perpetrator's location; the perpetrator(s) lives/lived in the neighborhood where the abduction occurred, as only the homes in that neighborhood were being searched on Saturday, October 6. According to former FBI profiler Van Zandt, the placement of the backpack may have been a red-herring to divert police away from the perpetrator(s). Because the only houses being searched on Saturday were in the victim's neighborhood, the perpetrator(s) might have left the backpack to divert police away from their residence in the victim's neighborhood.
The temperature on Saturday between 6:45pm and 1:00am was approximately 25-30 degrees fahrenheit. It seems improbable (to me) that the perpetrator(s) spent considerable time looking for a place to drop the backpack due to the increased police activity in the victim's neighborhood. Therefore, I propose that the perpetrator(s) drove purposefully to the location where the backpack was later found. This, IMHO, indicates a familiarity with the neighborhoods nearby to where the victim was abducted.