The Match (Wilde #2) by Harlan Coben

'At the age of somewhere between 35 and 45 - he didn't know exactly how old he was - Wilde found his father ...'

Wilde has grown up knowing nothing of his family, and even less about his own identity . All he knows is that, as a young child, he was found living a feral existence in the Ramapo mountains of New Jersey.

He became known simply as Wilde, the boy from the woods.

Now Wilde has had a hit on the DNA website he has been researching. A 100% match. His father. They meet up, and Wilde soon realises that his father doesn't even know he had a son and is as mystified as Wilde is by his existence.

Undaunted, Wilde continues his research for his family on DNA websites where he becomes caught up in a community of online doxxers, a secret group committed to exposing anonymous trolls.

Then one by one these doxxers start to die, and it soon becomes clear that a serial killer is targeting this secret community - and that his next victim might be Wilde himself ...