Benson is taking Noah home after dance when Simon shows up. She sends Noah to go get ice cream. Simon says his ex took the kids. He didn't tell her because he didn't want to make more trouble. He says he's been clean five years and she's his only family.  He pushes her to have lunch.

Meanwhile, a girl in the projects walks home eating ice cream and goes up the stairs. She hears a door close behind her. A man grabs her from behind. She drops the ice cream.

By the time the cops get there, there's a crowd of people gathered, angry that the cops don't protect people in the projects. Kat has arrived already via the subway. Kat has made a connection with the victim so Benson lets her question her. Lupe tells her that a man attacked her and said if she didn't have sex with him he'd attack her little sister.

Lupe's mother feels guilty. She had to work double shifts because her husband died of 9/11-related cancer so she couldn't be there. She can't give them any info and just wants to see her daughter.

No leads except the perp's hands smelled like shavings and were callused. Rollins finds out that DNA on Lupe's headphones match the DNA under the fingernails of a murder victim from 2003 that has been closed. Neither of the boys who confessed to the murder matches the DNA.

Carisi and Fin talk to Carlos, who says he's innocent and confessed because he didn't want to get the death penalty. Carisi and Fin don't believe him. Carlos says he swears he came home and saw the victims lying there. He can't say where he was hanging out with Ricky because of the guard standing there. He has a letter from Ricky but won't talk about an alibi and goes back to his cell.

Rollins and Kat talk to a Ms. Baker who claims Carlos wouldn't hurt his family. Ricardo died of AIDS. Ms. Baker blames the detectives.

Next, Rollins and Carisi talk to the detective who arrested Carlos and Ricardo. He insists they were the killers.

Carisi has brought back canolis. 

BEnson realizes they are looking for a serial rapist who has been out there for 16 years.

There are now eight suspects and three other victims.

Rollins and Fin talk to a maintenance guy who claims he can't help. He won't give them DNA because he doesn't trust the government. He's the first guy to say no. Fin finds a cigarette butt.

Noah is upset because Simon hasn't shown up and he doesn't want to be late to dance class. Benson calls Simon and tells him not to call her ever again.

The DNA matches but Benson wants Lupe to make a positive ID.

Rollins apologizes for what she said about Simon. Benson says that actually Rollins was right.

Lupe didn't see anyone. She IDs the suspect when he complains he doesn't want to read the line. He claims he worked in the apartment. He asks for a lawyer. Carisi says to keep him in holding while he talks to Carlos. Carlos IDs the suspect.They have to tell Carlos that Ricardo died.  Carlos doesn't think this will work out because the DA made his career on putting him away.

Carsi meets with an ADA in Queens who says you havven't heard about Keene.

Keene is in a wheelchair and seems out of it. He has dementia.

The defense attorney is obnoxious and says, among other things, that Carisi won't win because he used to be a cop and juries hate cops. The suspect starts shouting anti-gay stuff and that ends that meeting. Carisi realizes this is why Carlos won't talk about his alibi.

Fin asks the guard to leave for a minute. Carisi tells him this is confidential. He asks where Carlos was. Carlos says he was at the beach -- Plum Beach,w hich is a beach for gay men to meet each other. He and Ricky hooked up there.

Carisi tries to tell him times have changed. Carlos says not in jail, they haven't. Carlos has accepted he is in jail for life but wants to know where his family is buried.

The ADA says the best he can do is protective custody. Carisi says Carlos will kill himself in solitary. The ADA says he wll think about it.

Lupe's mother doesn't want her to testify. Lupe wants to do it to protect her little sister.

Benson gets a call. It's bad news. Kat asks what's going on. Benson says it's a family thing and she has to go.

Benson IDs Simon's body.. Warner is sorry. Apparently it was a heroin OD. He'd been clean for a while. It wasn't a suicide. 

Keenesigned the order -- the ADA pretended he was signing a law school recommendation.

They go to court. The judge apologizes for Carlos' wrongful imprisonment and vacates the unjust conviction. Carlos is released.

Stanton pleads guilty to the murders but not Lupe's rape. Lupe will not have to testify.

Kat takes Lupe and her mother home. Rollins asks if Benson is okay. Benson closes the door and tells Rollins that Simon is dead. She tells her about the message she left him. What if that was the last thing he heard? Rollins says she doesn't know that. It was more likely it was just his time.

Carlos goes to his family's gravestone and puts flowers on it. He cries.