Naperville, IL police and the Will County State’s Attorney announced an arrest in the 1972 murder of 15-year-old Julie Ann Hanson.

https://www.chicagotribune.com/suburbs/naperville-sun/ct-nvs-1972-homicide-naperville-hanson-st-20210604-wch5yl6bmjan7l4atlt3t36or4-story.html?utm_source=newsletter&utm_medium=email&utm_campaign=Breaking News&utm_content=861622820958#nws=true

https://abc7chicago.com/naperville-cold-case-julie-ann-hanson-murder-police-will-county/10742881/

The case was solved through DNA evidence and genealogy research. It can be done. That is, as long as a police agency does not give up on or bury a case. I’m guessing these two Illinois law enforcement agencies did not have a tiny fraction of the budget the OCCK task force did.