Yeah, I've camped hundreds of nights by myself in public campgrounds. Only twice ever had an issue. One was a youngster who got into my stuff while I was out for the day; LE evicted the entire family for lack of supervision. The other was someone who came through the bushes in the dark. He needed help because he'd never set up a tent before! And it was pouring with rain. And he had no flashlight (he'd never seen a headlamp, either, lol). His instructions had dissolved in the rain, lol. First thing I told him: "NEVER come through the bushes. Always approach someone else's site from the road." Then I set up his 8-person tent.
I've only ever had those 2.
But wasn't there a host at the Maquoketa campground? There are people usually up at the crack of dawn, too. Big RV owners tend to want to get on the road super early, and sometimes seniors (a significant proportion of campers) don't sleep well, so they're up 'n' at 'em.
I hope LE got more info from other campers, even if we aren't privy to it.