Is it possible that the police already know that it’s a homeless or illegal camp, and don’t see a reason to investigate further?
Sure it is possible.
But if so, they should go (with a news crew to get the word out) and tell the people there, that they are wasting their time rather than (apparently) studiously ignoring the ‘evidence’ and treating the team ( who’s main volunteer job is finding and helping homeless veterans) like they are the criminals.