When a young girl goes missing, they try to find her. They find her dead. They try to find out who killed her. DNA on her body is matched to a man in CODIS. The man is not the killer but the killer's brother. They ask him who his brother is but he can't tell them because he doesn't know. It seems like he was adopted and he doesn't know who his biological father is. He knows who his mother is but has never met her. They go to see her and she says the father is a man she had an affair with who was married and he has two sons so they think it could be one of them. So they go check his sons but they are not a match. They learn that the father was with many women. And they eventually find a woman who has three sons and one of them could be the one. Dodds finds working the case a little unnerving.
Did You Know?
When Olivia is searching for Noah at the playground she finds him on the ground with other kids. When she nears the tree across from where he is there was no one standing there. The scene quickly loops and now there is a man leaning against the tree. Not a goof: the tree is large enough to hide a grown man from the angle Olivia approaches. See more
[after Carisi lists all the evidence they have
Yeah, but don't know why
There's never a good answer to that question