What's this episode of Law and Order: SVU?

It starts out with a blonde girl and her brother running through a crowded street. The girl gets hit my a car and dies, and the boy is brought into the police station because they think he pushed her out in front of the car. But then it comes to light that both the boy and girl have been being abused and they're malnutritioned. Then they set up some thing to get the boy to talk or something - it's Finn in a car and he rolls up to the boy (who is being a prostitute) and they get him in the car. And apparently the boy and his sister lived in a foster home, but the people running it were abusing all the kids there. They had them in cages or tied up underground or something. I don't really remember. But it was a really good episode. And if anyone can help me, that'd be wonderful. It wasn't that long ago. In season 10, 11, or 12, I believe. Thanks for the help.