>> when police went to question him, he was gone. neighbors said he hadn't been around since olamide went missing. >> he did not have a vehicle. and the fact that olamide's vehicle was missing, that pointed even more directly towards wallace. >> nationwide alerts were issued for wallace and for olamide's car. >> when we say that yes, we had reason to believe that he's involved or has knowledge, that does not rule out that there could be other individuals. there very well could be. so, we're still looking at that, because we don't have all the pieces put together yet. >> wallace's credit card activity showed he purchased gasoline in mississippi the day after olamide disappeared. the gas station was near the barn where olamide's body was discovered. >> what we hoped to find out was did he purchase gas or an accelerant there that could be used to start the fire?