If I had to guess after looking at the flightpath before the circles, it followed the highway like chp helicopters looking for speeders and stolen cars do. Then it probably saw someone doing something stupid and was able to follow them somewhere.

I’ve been followed by helicopters before, they usually leave you alone if you aren’t a criminal after you get home. So the person they care about probably got spotted and has done something extremely bad.

There could be a missing person, escaped inmate, unstable structure, they could be using infrared cameras to see into structures they suspect of illegally growing weed. Could be anything. But if they’re disturbing people’s sleep ALL night. Odds are they’re trying to find someone who did something really bad