In my newest novel, Shades of Black, one of the protagonists suggests that our knowledge of serial killers is built on information learned mostly from the stupid and unlucky ones - the ones that got caught. He suggests that the best ones are never caught.
This guy might fit that profile. If the allegations are correct, this guy operated for decades and was only caught when he matched in a DNA database. They weren't even looking for him at the time. It's what they call in the detective novel business a fluke.
In writing Shades of Black, I did a lot of research on serial killers and this is the conclusion I have come to. Most don't seem to be caught using painstaking police work. Many are caught by accident, by flukes, by cops getting lucky. Many who are caught are only caught after operating for years right under the noses of the police.
I don't have any data. I could be wrong. This is just the impression I got. Maybe I should make a database and see if it bears out. But honestly you can't study this stuff for too long at a time. All that business about looking into the abyss - it gets to you.
Shades of Black is a supernatural noir.