If we assume that Nevaeh disappeared earlier than what was reported, we can go back as early as about 3:30 when the upstairs neighbor said she left his apartment. Whether or not Jennifer and Nevaeh actually went to KMart after that seems to be unproven at this point. We would also have to assume that no one saw Nevaeh after 3:30 and that the story of a child telling on her for riding in the street either happened earlier or not at all. That leaves the time from 3:30 to 7:15 for George to snatch Nevaeh, harm or kill her, and bury the body. Two witnesses who took polygraphs give him an alibi from 4 to 7. Apparently he also has an alibi (people he drove, getting gas, etc.) after 7.
In order for him to be the perp, George, Savannah, Savannah's mother (I'm assuming), and Jennifer would all have to be lying and be able to fool a lie detector test. I'm not buying it.