It is very likely that this series of the murder of 4 children is related to other crimes against children.I'm a firm believer that this set of crimes, and other sets of crimes against juveniles around roughly the same period of time along the Great Lakes, could very well be related in various ways. The Double-Initial/Alphabet Murders in my hometown come to mind, at least the two that LE know for sure are a mystery. Others happened elsewhere along L. Erie. One more that comes to mind is the Tammy Jo Alexander murder (formerly Caledonia Jane Doe).
What I'm driving at is I think various perps in these cases may have known each other.
The fact that the perpetrator had committed so many separate murders in such a short space of time indicates that he had been "working up to it" earlier. Perhaps not abductions and murders, but certainly committing other crimes against children. And he could not have simply turned it off and cured himself immediately afterward. There were more.