I might think that except for the overwelming red flags on this one. She was not estranged from her family. She left behind her purse, cell, cloths, Id. She took nothing. She had just bought the cell. Paid for it herself. Her ID was in the possesion of one of Walls' friend. Walls called his ex g/f from that cell phone...made over 300 calls, and the calls were not to find Roxy. Wouldn't he have thought she would be mad when she came back...no, because he knew she wasn't coming back. There's more.
I wonder how many of the calls made were to known friends of Roxanne to make sure that she was okay. Walls said that he later went to look for her. If Walls was looking for Roxanne chances are they will run into at least one person and ask if that person saw her. He would have called her friends or someone to ask if they had seen her. He had no vehicle, so did he only look on foot? Or, did he call a friend to help look more efficiently. If he was truly worried why didn't he call her home that very night to see if she got home safely?
LionRun