This is a great call, these folks aren't devious or clever enough to understand that they can just ask...

Even more devious would be "submit DNA samples and we'll give you immunity from paternity lawsuits", since concerns over that might inhibit some.

Nobody who needs protection from a paternity lawsuit would fall for it.

Oh, my sweet summer child. Have you met any teenage boys? Or most philandering men?

HN Search: GEDmatch - https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

A murderer was caught because he was semi-closely (2nd-cousin) related to my cousin. Her DNA was a loose match to evidence. They found out she is The Geneologist for our family, and asked her to help... Boom, found him.

You just follow them around until they throw their lunch in the park waste bin, then collect their DNA off the garbage. No need to compel anyone.

That's the end game, but first you have to figure who to follow around. To do that, you triangulate with public DNA data of somewhat distant relatives. Forensic genealogy.