Nobody notices? How about the people who live there, how about the people who knew the kids? Or let’s just ask the parents if they don’t care that their children disappeared.
Some of Gacey’s victims had been missing for months-the parents (apparently) thought they had run away to live with friends. Many of these kids had been in trouble with the law..and the parents were burnt out dealing with them.
A lot of high-profile cases end up with copycats. A lot of the time police end up fearing them more than the original serial killers. So doubtless there were some cases that just went with the flow.
Serial killers are rarely tied to all the murders they commit in a legal sense unless they confess. Even then the confessions cannot be trusted. I think there was one drifter in the early 20th century who certainly did kill some folks, but the police from several states just kept piling unsolved cases in front of him and he confessed to all of them.
Wayne Williams probably did a lot of the murders, but probably not all. One thing is certain - this was not a ‘KKK’ crime. White people trying to lure black children in these neighborhoods would stick out like a sore thumb.