maybe something in his body language when he was first interviewed, he was interviewed twice before the search giving a 10 page statement, he may have said something strange setting off alarm bells and his van was probably spotted outside williams grandmothers on the days after, then posting on facebook and maybe even joining in the search, like the perps who keep appearing too helpful and concerned,
he may have been under surveillance and could have a bit of a history.
maybe the investigation into the cars was to see if anyone saw his van at 10.30 driving into kendall?