I didn't see the whole thing, but I did see a bit of it. In one part, they went through how they misled the nuts so they could get more evidence against them, for charges that were not just the misdemeanor.
Having people think cops are dumb is one of their best weapons against perps.
yes, i definitely agree. I have been thinking all along that the cops were taking the Colombo approach of only pretending that they didn't suspect this family of putting on a show for everyone. It's the smart thing to do and the father, especially, was probably so convinced of his ability to con people that he probably had no doubt that he had fooled the police.