http://www.mlive.com/news/muskegon/index.ssf/2013/06/jessica_heeringa_case_2_months.html#/0
"Norton Shores Police Chief Dan Shaw said Friday, June 28, that the case has had some movement, and while there have been “some people of interest,” it’s difficult to tie them to the alleged abduction."
We are still receiving a few credible tips a week and we jump on those right away,” he said. “There’s more than one person who knows what happened. We need someone who knows to finally step up and guide us in the right direction to make it happen.”
Is Dan Shaw saying that the abductor and Jessica knew what happened, or is he saying that besides Jessica, there's more than one person (possibly that he believes) who knows what happened?