I think that there is something to be learned from looking at the timeline again and making some hypothetical scenarios that would fit within the constraints of the timeline.
Option 1.
1. Sierra took her own picture willingly and tweeted it at 6.29.
2. Sierra sent her friend a text at 7.11 regarding classwork.
3. The phone was discarded on Palm ave. at 7.15.
Given the short amount of time between the text and the phone being tossed, it would stand to reason that she was not attacked in the house. The abduction happened after she had left the house but was still in her yard.
Option 2.
1. Sometime after her mother last saw her at 6.10 or whenever it was, someone came into the house and forced her to send the picture.
2. That person also made her send a message to a friend at 7.11.
3. She was removed forcibly from the property and her phone was disposed of at 7.15.
This scenario seems highly unlikely to me, because the fact that she did not reply back to the friend that she sent the 7.11 text message would certainly be more of a signal that something was wrong when she failed to show up for school.
So I am leaning toward the first scenario, and would wager that it was someone she knew who ultimately abducted her. I say ultimately because I think it was not initially an abduction, but she went along willingly.
(snipped for space)
Just a quick clarification, the picture was not tweeted, cardozo was mistaken when he said that. It hasn't been confirmed what happened but since I myself switch tweet with text and vice versa, and I do both all the live long day and know the difference, my belief is the photo could of potentially been sent by text even though it looks more like a webcam composition.
Another option
1. Sierra is reblogging and sends one retweet, sitting on her computer, half ready for school, about 630.
2. Sometime after this, one or more people enter the home, and a grave situation develops immediately.
3. They know Sierra well enough to know she is meant to be leaving at 715, with her phone, and a bag. A photo and a message is sent to help point to the crime starting outside the home.
4. You can restrain small Sierra by overpowering her, but you sure as hell cannot put on her shoes without a lot of fuss. A vehicle comes from an obscured part of the property nearly to the front door and Sierra is placed inside very quickly, the vehicle leaves, looking to any potential witnesses as expected and familiar traffic.
5. Drive away, quickly tossing her phone. Is the bag placed soon after or on the way back? Not getting the shoes was an error in pointing to her being on her way that day, when the crime has been quite planned, but everything else that left with Sierra is found rather simply.
I don't buy that any links with illegal goings on could have been fully examined in the few days before the parents were cleared. Not to cast any suspicion on Marlene or Rick themselves, or the property/business owner but sometimes good people get tied up with scary and dangerous people.