It's One of Us by J. T. Ellison - 4 stars

[Ellen]

Olivia Bender and her husband Park have been trying to have a baby for several years now. Fertility treatments have not produced a child and Olivia is nearly resigned to being childless. After a woman is murdered in their town, the police come to see Park stating that his DNA is a match Park's son. Park swears he has no children but does admit that when he was in college he donated to a sperm bank. Olivia is devastated to learn that Park has a child and quite possibly more than one. And this one is a killer!

16-year-old Scarlett has always known that her mother used a sperm bank for herself and her older brother. She always longed to know her father and decided to submit her DNA to a reputable DNA research center. Scarlett soon learns that she has several dozen half brothers and sisters and she begins a private internet group where they can all discuss their lives. When she learns that one of her group is a possible murderer, Scarlett is shocked. Another woman in town goes missing and it is believed that the same person has kidnapped her.

At Olivia and Park's home, things begin to disappear. It is obvious that someone has been getting into their house. They are sure that it has to be Park's son but they are not sure what his agenda might be. Whatever he is up to and cannot be good.

What an interesting setup for a mystery. It makes for quite an intriguing story. And there is a heck of a twist at the end that I sure didn't see coming. Well done.