Stark prosecutes a racially-charged murder case involving one of Julie’s friends.

In Brentwood, a car deliberately runs down a drunken teenage girl who has just left a party. Stark is on a date with a yoga instructor when he sees the incident on the news. The girl is not identified; Julie’s at a party in Brentwood tonight. Stark races to the crime scene, and pushes through a crowd of affluent white folks and black kids from Compton. He’s relieved to see that the body is not Julie’s. Julie then runs up, and tells Stark that she tried to call but her battery was dead. She says the girl’s name is Erica Hartford. Julie didn’t see what happened; she was inside. Raina says the girl lived in Compton and had a scholarship to Southlake Prep, a school mostly filled with rich white kids. Stark realizes the press could blow this up into a huge racial incident.

The next day in the bullpen, the team goes over the case. The kids at the party say there was tension between the Compton kids — who were all friends of Erica’s — and the white kids from Southlake. Two of Erica’s friends have criminal records. They need to find the car. Poe asks if it’s okay if they talk to Julie; Stark hesitates, and then agrees. Julie tells Poe that she knew Erica through her friend, Cat Crosby. Erica and Cat were really close. Julie says she didn’t notice any tension at the party aside from normal party shenanigans. Afterwards Stark warns Julie to be careful what she says to the press.

Stark finds former Detective Isaac Wright, now working in private security, and hires him as an investigator. Isaac and Raina go to Compton to interview some of Erica’s friends. When Raina tells one kid, Anthony, that he was seen arguing with a boy from Southlake, Anthony tries to walk away. Isaac threatens him into talking. We then hear the story from both Anthony and — in an interview with Poe — Gia, the party’s affluent 17-year-old host. Their stories mesh. It was a normal party; there was drinking, but nothing out of control. The black and white kids have partied together before; no big deal. The last time Erica was seen she was upstairs with Ben Channing, Cat’s boyfriend of two years. Both Anthony and Gia say that it was hard for Erica to straddle two worlds. She was never really going to fit in with the rich kids. Gia thinks Erica had a crush on Ben, and then Cat found Erica and Ben together in the bedroom.

Jessica and Stark confer; pundits on both sides are playing the race card, and stoking tensions all over LA. Stark says it looks like it’s actually a jealous lover case… and a BMW reported stolen that night was registered to Cat Crosby.

Martin and Raina question Ben. Ben says Erica had been upset because she was worried that people would be mad at her that so many of her Compton friends had shown up; it wasn’t the case, but it was something she worried about. He was just trying to calm her down. He was seen arguing with Cat that night; Ben says it was just a normal relationship fight, and denies any romantic involvement with Erica. He doesn’t know where Cat is; she’s taking it all pretty hard. Poe and Casey talk to Cat’s mother, who becomes offended when she realizes that they’re suggesting that Cat is a suspect.

Isaac calls Stark, and says Cat’s BMW has been found in Compton with blood and fabric on the front bumper. Raina says Cat Crosby’s cell phone has been traced to Laguna. Casey, Isaac, and Raina go to the location, where they find Cat unconscious from an overdose of sleeping pills and alcohol. She’s taken to the hospital; she’ll live. Stark has her arrested immediately.

Five days later the judge is set to deliver a ruling on whether Cat’s ready to stand trial. She nearly rules against, but Stark persuades her that race riots might break out if rich, white Cat is cut any slack. Now they need to prove that Ben and Erica hooked up that night, and that Cat’s car wasn’t stolen. They also need to convince a white jury on the Westside to stand up for a black girl from Compton.

Poe and Casey get Ben to admit that he was seeing Erica. The day of the party Cat found a letter he had written to Erica telling her how he felt. He still insists that Cat couldn’t and wouldn’t have done it. How did the car get to Compton? Isaac finds that Andrea Crosby used her credit card at a gas station in Compton that night. The clerk can ID her Mercedes, but not her. Poe notes that Raina is attracted to Isaac; Raina says she doesn’t do office romance. “Who said anything about romance?” says Poe.

In court Raina argues that Cat killed Erica in a jealous rage. Lauter, the defense attorney, says he can prove Andrea wasn’t in Compton that night to help Cat; and that an expert in vehicle fatalities can prove that it was an accident, not murder. Stark tells Martin to find this expert, and tells Raina to find a witness fast. Julie stops by, and tells her father that Cat wouldn’t have done this. Stark says all the evidence points to her; there’s nothing he can do. Casey pops in, and says they found a witness who saw Cat Crosby at that gas station… but with a teenage boy, not her mother. Ben is questioned again. Now he says he and Erica had been making out, Cat caught them, and then Cat mowed her down. Ben didn’t call the police because he blamed himself for the situation. Stark offers to reduce the charge to vehicular manslaughter and try Cat as a minor; her mother won’t take the deal, against Lauter’s advice.

Jessica tells Stark that Julie told her school paper she thinks Cat’s innocent; the national media are running with it. Stark angrily confronts Julie, and tells her she’s poisoned the jury pool. In court the expert in vehicle fatalities shows a computer simulation he says is “99.37%” accurate. Stark shows the jury another simulation he’d run of a plane crash, and determined to be an accident… until the pilot’s suicide note was found in the wreckage. The “expert” is a phony. Martin, however, reports that Ben’s juvie record includes convictions for shoplifting and vandalism; there goes his credibility.

Raina interviews Erica’s mother, Ruth, who says that Erica felt out of place at Southlake until meeting Cat and Ben. Suddenly she was happy and smiling. She listened to a mix CD of love songs at night over and over again. Raina asks Ben what was on that CD. He can’t remember. Stark asks Julie if she remembers the stuff she’s put on mix CDs for her boyfriends; she says of course. Isaac and Raina take Ben to Stark’s office, but claim to have to stop at Erica’s on the way. Ben obviously doesn’t know the way, and has never been there before. Stark is frustrated, but Poe has found video from Erica’s computer: cell-phone footage that shows it was Cat that Erica was having the affair with.

Cat offers to plead guilty to second-degree murder on the condition that her relationship with Erica is left off the record. Stark won’t accept the offer. The judge gives Stark 24 hours to go to trial or drop the charges. Jessica is incredulous that Stark is turning down murder two, but Stark says he honestly doesn’t think Cat did it. Jessica accuses Stark of letting Julie influence his judgment, and says if he can’t nail somebody else in the next 24 hours, she’ll accept the plea herself.

That night Julie apologizes; she was mad at Stark and felt he wasn’t listening to her. They end up in a heart-to-heart about the first time she fell in love; they wrote each other long notes, and she kept every one of them. Stark has a brainstorm, and has Cat’s mother’s car searched; a note is found. It’s a love letter from Erica to Cat. Stark keeps its contents to himself until he can talk to Cat. He shows her the letter. Cat says she loved Erica, but feels guilty for cheating on Ben. Stark says Erica wouldn’t have wanted her to throw her life away for a lie. Cat says it’s all her own fault. Ben found the letter, and had been yelling at Erica at the party. Cat arrived, and tried to calm him down. Then they decided to leave. Cat was a little drunk, so she gave Ben the keys. They saw Erica walking down the road. Ben said he wanted to scare Erica a little, and then he ran her down. They went and got her mom’s car, and she followed Ben down to Compton, where he dumped Cat’s car. Cat didn’t call the police because she didn’t want Ben to get arrested for something she thinks she “made” him do. Stark tells her it’s Ben’s responsibility. Cat begins to cry.

Ben is arrested. Julie thanks Stark for helping her friend. Then Stark says that all the things in her life he always says he didn’t want to know about, like sex and drugs… well from now on he wants to know.

10th May 10pm On Five