He's right under their nose...or perhaps nearby. It's that simple. JMHO.
Occam's razor theory: Occam's razor (or Ockham's razor) is a principle from philosophy. Suppose there exist two explanations for an occurrence. In this case, the simpler one is usually better. Another way of saying it is that the more assumptions you have to make, the more unlikely an explanation is. Occam's razor applies especially in the philosophy of science, but also more generally.
https://simple.wikipedia.org/wiki/Occam's_razor
Just a theory of course. Sometimes the closest to home or the area, or those that regularly visit the area...worth a revist by LE or a fresh set of eyes.
The simplest solution, regardless of how unlikely it may seem, is typically the correct solution.