They do it not inadvertently, but deliberately, because something like this is the stuff of Pulitzers and at worse you get to travel to someplace that now is safe even if your stupid questions do nothing more than annoy the police & public.
News reports show the killer's name over and over until it is etched in our brain, along with his ranking. And the old record of 30+ still stands, and by now even the dullest realize, how many more will you have to kill to get on the news?
"Oh! I got it. I'll kill small children. That'll get their attention." And so it did.