Maybe this is what he did: He takes Sierra by taser, puts her in the trunk, takes off, his adrenaline is probably pumping about now. He goes up 3rd heading northward instead of turning around, he goes up scheller ave, throws the phone, at this time I think Seirra while in the trunk has started to make a lot of noise in the trunk, no longer tased, and she is fighting, kicking, screaming...he has to subdue her, which means he has to pull over somewhere quiet out of the way. He turns right, and see's the old building from the main drag on Fisher and goes there, pulls in, notices nobody around, has the vehicle out of sight, opens the trunk, and this is where Sierra was killed. After he did that, he put her back in the trunk, and headed back down closer to his home, or where he was more familar, UVAS area, in or by that area to get rid of her body.