I could not agree with you more about the damn bag having bugged the crap out of me sense the get go..there is something just not right with it being in the case, period.. it does not fit in more ways than one.. so ill go ahead and say what's been in the back of my mind and the only way I can make the bag fit..
Please hold the tomatoes this is nothing more than a theory of the thousands already listed..
Here goes.. I am not going to even theorize on who the perp could be but rather just give the basics of how I see this purse fitting.. IMO it wasn't ever part of Sierras day.. meaning she never left with those clothes or books in that juicy bag.. IMO that juicy bag did not come into play until after Sierra had already been harmed and possibly even disposed of or hidden.. I believe the idea about the bag was an afterthought for staging purposes.. I believe that the perp in a desperation to make it look as tho she was either taken on her way to school or had runaway the perp grabs the juicy bag, puts the clothes inside, gathers the school books and goes out and randomly hides these items where they were eventually discovered.. they wanted these items to eventually be found so that it would point toward Sierra being abducted while en route to school.. or that it may even be assumed as some sort of runaway with the clothes packed.. regardless of which one of those the important point is that it completely redirected LE and everyone from the real perp, and the real crime..
Yes, obviously the perp would have to be someone with access to the home.. but I'll leave it at that.. in the above described scenario the bags purpose, the bags contents, and even the bags placement suddenly all fit together..
There it is IMO.. IMO its why we cannot make sense of the damn bag.. jmo, tho and I am making no accusations.. :moo:
Eta: it would also make sense for why her normal things weren't in the bag.. make up, keys, brush, wallet, etc.. because she did not pack the bag.. the perp packed it after the fact as a way to misdirect attention from the real perp and real crime to an abduction or possible runaway.. jmo..