Apparently he was a queer killer. He picked his victims at gay bars then lured them in to his home.
Advances in technology now make it possible to identify more victims by extracting useful DNA from previously recovered bone and teeth. In spite of the expense of so much DNA testing, homicide detectives and crime labs regard such an effort as a matter of professionalism and dedication to murder victims and their families. In a world with so much evil on the loose, that is cause to take heart.
Didn't John Wayne Gacey do something similar? He picked up young men on the streets of Chicago, who were selling themselves.
The mistake that got him caught, was luring a young boy to his home, the teen was looking for summer work to save for college, then killing him. This wasn't some runaway. This kid had a family who missed him; and, Gacey was seen with this kid, at a local hardware store, before he "disappeared".