A girl is found rapped and almost beaten to death. She is rushed to the hospital, but dies a few minutes after going into surgery. Elliot finds the girl's jacket and a bottle of percosed belonging to Emily Porter. They track down Mrs. Porter and her daughter confesses she sold the pills to a dealer in the park.
Fin busts the dealer and he tells Fin the dead girl bought the drugs and went to a motel nearby. The motel receptionist recognizes the girl, and says she met an older man at the reception, they argued and he dragged her into his room. Olivia and Elliot search the room, but the room hasn't been cleaned in a long time, so any fluids they find there are useless. They find a hat, and it's exclusively made for one store. The store says the hat was shoplifted, and even have the picture of the girl in their black book, but no name. The manager says they pressed charges and give them the police officer's name. Elliot and Olivia talk to the officer and discover she is that step daughter of a Judge.
The Judge is an old friend of Captain Cragen and he decides to step in the investigation and notifies the family. Judge Walt Thornburg tells the Captain that Patricia was a troubled child ever since he married her mother, and she was sent to a boarding school for some time, but was back at home for almost a year now.
Olivia and Elliot talk to the nuns at her school and they tell them she was rebellious, skipping school, cutting herself... Her only friend at the school tells them she had been pen-palling with convicts. ADA Cabot realizes all the convicts Patricia was corresponding with were sent to jail by judge Thornburg.
Meanwhile Olivia and Elliot are notified that the judge has just been shot outside his house. They both go to the hospital and talk to his wife, she says she didn't see anyone, she just heard the shot. Olivia asks her if she ever heard her daughter mention the name Thomas Gordon, one of the convicts she was writing to.
Fin and Elliot talk to Tomas's parole officer, his employer and co-workers. One of them says Thomas borrowed his van and didn't return it yet. Captain Cragen puts an APB on the van. Olivia finds the van and a gun inside it, and they take it to the lab to match it with the bullet from the judge. Elliot and Finn arrest Thomas and the lab matches his DNA to the one found in Patricia. The gun is also a match to the one in the judge.
Thomas tells them Patricia was the one that started to write to him, promising sex when he got out of prison. They met in the motel the day she was murdered, he says she was supposed to give him percosed in exchange of a favor. She said she would have sex with him if he killed the judge. He claims she was alive and well when he left.
Elliot and Olivia talk to Patricia's aunt and she tells them Patricia was never in boarding school, she was in a kid's correctional facility. Fin talks to the director and discovers Patricia was sent there when she was 12 to conceal a pregnancy. Olivia and Elliot confront her mother and she says Patricia never told who the father of the baby was, she says Patricia told her she didn't know who the father was.
They investigate and find out that the judge's adopted son has the same birth date as Patricia's son. They suspect Patricia was sexually abused by the judge and the boy is his son. ADA Cabot gets a warrant to get the boy's DNA and run a paternity test. The test is done and it proves judge Thornburg molested Patricia and is the father of her son.
Captain Cragen talks to the judge and he still denies he killed Patricia. Olivia and Elliot go to the lab and find a fingerprint in the bottle that killed Patricia, it is Mrs. Thornburg's. They confront her and she confesses she went after her when the school called, they had an argument about her pregnancy and Patricia finally told her who the father was, she says she just snapped and hit her with the bottle.