A woman (Nina Wilshire) is found shot to death in her apartment, and Detectives Bernard and Lupo are called in to investigate. A neighbor called the police after she heard gunshots, and she also heard the fire alarm go off, which means that the killer might have exited through the fire escape. The detectives find that Nina has several expensive paintings in her apartment, and Lupo thinks that Nina might have been shot when she opened her door, judging from the wounds on her body.
The detectives inform Nina's mother about her death, and they question whether Nina was involved in anything illegal like drug deals. Nina's mother doesn't think so, since she owned her own interior design business. Her mother then shows the detectives photos of her daughter, which both Bernard and Lupo figure out is a waste of time.
Later, they speak to Van Buren about having to look at photos for two hours and not getting anywhere with the case. Ballistics have figured out that two different guns were used, so they know that there were two killers. They go over the security camera surveillance video and watch as Nina goes to the front door and struggles with someone. There may be a print from when the stranger hit his hand on the glass door. They ID the print as belonging to Dr. Lucas Nevra, who is a chiropractor and whose office Nina was scheduled to decorate. He says he did talk to Nina but she canceled three appointments they had after he gave her $5000 to keep her on retainer. Nevra adds that the $5000 wasn't that big of a deal, but he seemed really upset on the video.
The detectives find that Nina barely had any banking accounts, just a single account for $10,000 which was never touched. Perhaps those expensive paintings were her way of laundering cash.
Meanwhile, Van Buren is having dinner with her son - home visiting - and her boyfriend, Frank. Van Buren has no appetite because of the chemo and her son offers her some medicinal marijuana he got from a nurse in the cancer ward. However, medicinal marijuana is still illegal in New York, so Van Buren is upset by the offer. Later Frank says that her son only wanted to help and that he didn't fall in love with a stupid woman. The marijuana would help her a lot if she took it. He leaves her alone with the bag.
Lupo and Bernard go to the gallery Nina used to procure the paintings. The woman at the gallery explains that Nina had another apartment in the same building which she could have used for storing paintings. They search the apartment and find paintings, a lot of money, and marijuana. The DEA had been tailing Dr. Nerva for some time. He was a dealer and the DEA was trying to track down the name of his supplier. Lucas made to Nina right before she was shot. Lucas mentions something about getting ten grand to her, and Nina says that there's a kid at the door who needs help. Therefore, the killers might have used the kids as a ruse to get her to the door so that they could shoot her. But as the video shows, the kids weren't just a distraction, they were the killers.
A man who runs a fruit stand near Nina's apartment building says that he remembers the kids were playing soccer nearby. They didn't go into a car after they left, but there was a limo double-parked in the loading zone. The limo belongs to Riverdale Limo. The driver was waiting for three hours, and his dashboard camera caught a view of the kids as they climbed into a car, a Maserati. Bernard rattles off a lot of detailed info about the make and model of the car, and when the other detectives look at him in surprise, he explains that in Compton, he picked up a lot of info about expensive cars from the guys who stole them. They try to track down the Maseratis in the area, and then the Chief of Detectives starts to talk to Van Buren alone. He mentions that she smells of marijuana smoke, but when Van Buren tries to explain, the Chief says to save it and gives her some advice on how to mask the fact that she's smoking pot. He also gives her the name of a man who sells medicinal marijuana. The Chief explains that he had testicular cancer and is offering some sound advice.
At the car dealers, the detectives find out that the Maserati was sold to a guy named "Joe", who paid in cash. They get the salesman to help with a sketch of the man's face, and the salesman also explains that he got a message from the guy a couple of weeks back because he needed a mechanic. The detectives get the address that "Joe" gave to the salesman. Lupo and Bernard go to the address, where a car of girls pulls up. The detectives try to find out if they can bring the driver of the car in for anything.
The woman, Vasquez, is wondering why she was brought in for a traffic violation. The detectives try to pressure her with questions about her drug possession, but she asks for a lawyer. Later, Bernard, Van Buren and Rubirosa talk about the girls. The hundred dollar bills in Vasquez's purse all tested positive for cocaine residue. If she's a prostitute, then she was hired by the owner of the house, which leads the detectives to suspect that there's drugs in the house.
There's a police raid on the house and the kids living inside are taken in. They find a gun on one of the couches, but when they ask the kids about "Joe", the kids all deny ever knowing a "Joe" and that this was their house. Lupo counters that if this is their house, then these are their guns, and arrests them.
The three boys, Raphael, Samuel, and Carlos are in court and being arraigned for second degree murder. At first, a woman lawyer from legal aid says she is representing all three boys. Rubirosa says that she has no objection to all three boys having joint representation, but a new lawyer (Marcus Woll) comes in, saying that he's been hired by the families of the boys. Rubirosa recognizes Woll, and she knows that he's not the type of lawyer to work pro bono; someone must have retained him. When pressed for this info, however, Woll says it's not relevant to the case. These three juveniles had no criminal records. Woll also tells Rubirosa that there is a motion in court to suppress all evidence found in the house.
Rubirosa tells Cutter and McCoy that the guns found in the house are linked to the murders of drug deals in Philadelphia and Newark. The DEA says that these dealers were put on a hit list by a Mexican drug cartel, the Vella family. The kids were trained as assassins and retained in the house to go and kill as needed. But there's little proof which says why Nina was killed, since she didn't have that much power. Cutter wonders if they could get one of the kids to crack and tell them who Joe is, which could be the key to their case.
The lawyers say that since Vasquez is a known prostitute, then she was in the house to offer its occupants sex, and that since there was cocaine residue found in the money she received as payment, then there was cause to believe that there was drugs in that house. Woll counters that cocaine residue is found on 90% of all currency in circulation. The judge agrees with Woll and refuses to take evidence from anything found in the house. Woll wants to dismiss all charges against the kids, but since Raphael and Samuel are easily seen in the surveillance video, Cutter objects. The judge agrees with Cutter, but dismisses the charges against the other kid, Carlos. Rubirosa suggests that they should start talking to Raphael's parents.
The lawyers are in the parents' home, and they inform them that their son was trained as an assassin in Mexico. Mrs. Alvarez doesn't want to say much, but Rubirosa gets her to open up a little by talking about birria, the dish Mrs. Alvarez is cooking. Raphael didn't seem too upset about that girl, laughing about her. And he also sang a song about having no fear. Mrs. Alvarez is still reluctant to talk to them, but Mr. Alvarez was a little more open. Cutter wonders why Raphael was singing about the crime, but then they figure out why the stereo in Nina's apartment was hiked up to full volume.
The detectives and the lawyers are listening to a Hispanic song which was on Nina's iPod and as well as in the house the kids were staying in, about the exploits of a Mexican drug cartel. Drug ballads are apparently fairly popular in Mexico and Latin America, where the songs are about various crimes the families have committed. The cartels are somewhat seen like folk heroes. McCoy says that Nina was killed by the Vella family because she was featured in a song about a rival cartel. Rubirosa hopes that an old boyfriend may be able to identify the other cartel.
He says that the song is about the Ramon family, who are so cowardly and weak that they use a woman to do all their work for them. But now she's dead, with 4 gunshots to the face. This detail was not released to the public, so whomever wrote that song either did the killing themselves or knew about it. The name of the group is Los Guereros, which is the band for the Vella. The song was uploaded onto the internet the very night Nina was shot. And the band is about to hold a concert in New Jersey. Rubirosa, Lupo, and Bernard go to the club, only to find that the band has been shot dead.
They found the lyrics in a knapsack in the tour van, but the handwriting on the paper is different than for the other songs. They hope to be able to get some fingerprints from the paper. The prints are from a man named Eddie Blanco, who is fairly high up in the Vella family. Eddie's picture matches with the sketch of "Joe" which the salesman described earlier. They arrest Eddie, who immediately demands that he talk to his lawyer, Marcus Woll. Rubirosa wonders whether Woll would be able to represent both Eddie and the kids, but since Raphael is a minor, it's really up to his parents to choose who gets to represent him. Cutter tells the Alvarezs that Woll doesn't care anything about the kids, and would probably decide on just representing Eddie. Woll argues that Raphael is emancipated from his parents, so he should be able to choose who represents him. However, Cutter argues that then Woll would be representing all three defendants in the case. The judge rules in favor of Cutter and asks that a court-appointed lawyer be brought in for Raphael.
Raphael, however, wants no part in the planning of his case. Rubirosa goes to Dr. Burkhart for advice on house to deal with the boy, who has pretty much been brainwashed into loyalty to the Vella drug cartel. Burkhart tells her that sometimes a breakthrough can be triggered by a very small detail of the person's past. Later, Rubirosa is with Raphael and his lawyer, when Rubirosa suggests that they have lunch. The lunch she takes out is birria, made by Raphael's mom. She offers a plate to Raphael and he eats, and soon starts to cry.
Later Raphael takes the stand, giving testimony about being taken to Mexico and trained as an assassin for the drug cartel. He says that Eddie was the person who gave them their missions and he told them to go and kill Nina. He confesses that he did the killing, but never felt anything about it afterwards. The grand jury indicts Eddie Blanco, but McCoy mentions that they've found a song on the Internet which threatens Rubirosa. So she and Cutter have to be guarded at all times.
Lupo, in court, identifies the two boys who were on the videotape. Cutter brings Raphael as the next witness, but Woll counters that the boy shouldn't be brought in as a witness because he is a minor, and also has been under a coercive environment for the past two weeks and could be influenced by psychological manipulation. Cutter explains that he was in mandatory therapy, but the judge sides with Woll. Woll is given 24 hours and court is adjourned. Cutter says that the defense is stalling for time, and they should make sure Raphael has extra guards on him. Blanco and Raphael exchange glances, with the boy becoming very anxious in the older man's presence.
Rubirosa panics after she walks out of her place the next morning to discover that her security detail was not there. She's called to the juvinile detention facility. Samuel's throat was cut open and he bled to death before anyone could find him. Cutter talks to Raphael and tries to assure him that he won't meet Samuel's fate. But Raphael doesn't believe them.
Back at court, the judge denies Woll's motion to keep Raphael off the stand as a witness, but Cutter wants to give Raphael time to compose himself after the death of Samuel. Woll says that this shouldn't matter, because the argument doesn't change because of the death. The judge agrees and gives Cutter two hours to bring Raphael to the stand. Cutter and Rubirosa go talk to Raphael in his cell, who seems to have completely shut himself off. They talk to him, but he doesn't answer. He just keeps bouncing a ball on the wall.