As for the footprint on the box in the alley, there's a possibility that it's from the oldest son going in and out of the backyard for whatever reason.
I seem to remember a post from way back where someone stated the the 14 year olds 911 call made him sound "street smart". That's the first...
It is not unheard of, if PCSO is involved in a search, to bring in outside help depending on the terrain.
There is a group here (Arizona Rangers I believe) that quite often helps in local searches, most of these volunteers bring their own trucks, horses and trailers to the search site...