"The Crime Scene" is the sixth episode of Brooklyn Nine-Nine's sixth season.
Jake and Rosa work a difficult case where, despite plenty of evidence, they can't figure out who the killer is or how they got in or out. However, Jake foolishly promises the victim's mother that they'll catch the killer because she reminds him of his own mom. In addition, Rosa has a new girlfriend who's in Cosmetology school, and practices on Rosa's hair.
This episode provides examples of:
- A Bloody Mess: Jake takes about four bottles of ketchup into the break room, claiming it's for his hot dog. Turns out he's recreating the crime scene, covering the whole room in ketchup.
- Bottle Episode: The episode is mostly Jake and Rosa working on the case, with the other regulars only making brief appearances. The first half takes place entirely inside the apartment where the murder took place, although on multiple days.
- Chekhov's Gun: The Air Conditioner. It was mentioned earlier in the episode, and the CSI stated that they couldn't turn it on because it would tamper with the crime scene. When the crime scene was finally cleaned up and the air conditioning was turned on, it rattled objects in the air vent, which led to Jake discovering the killer's hiding spot.
- Conditioned to Accept Horror: Upon seeing the delivery man's Freak Out! over seeing the crime scene, Jake and Rosa wonder if their jobs as police detectives have numbed them to violence.
- A Day in the Limelight: For Jake and Rosa as a team. Holt, Amy, Terry, Boyle, Hitchcock and Scully only have a brief appearance each.
- Gag Haircut: Rosa lets her girlfriend Jocelyn practice her hair styling on her, leading to some amusing and out-of-character looks.
- Intimate Hair Brushing: Combined with Intimate Haircut. Rosa appears in a new Gag Haircut for almost every scene. She dates Jocelyn who's training to become a stylist and she practices on Rosa. Some of them are new cuts, some use hair extensions and she even wears one elaborate updo that would be ok for a ball, but is quite impractical for a detective working a murder case.
- Intimate Haircut: Implied between girlfriends Rosa and Jocelyn. Jocelyn is in cosmetology school and Rosa allows her to play with her hair and practice on her. She has a different hairstyle in every new scene.
- Knew It All Along: Jake, who had claimed at the beginning to have counted 15 CSIs, despite Frankie claiming to only have 14. Turns out, Jake did count 15; except one of them turned out to be the killer making his escape.
- Locked Room Mystery: The case is a textbook example. No person is seen going in or out and there was no sign of forced entry. It turns out the killer was hidden inside the walls and only escaped when the police came in, disguising himself in a hazmat suit to appear to be part of the team.
- Nice Job Breaking It, Hero!: Downplayed as he was really just doing his job and trying to avoid crime scene contamination, but the CSI Tech refusing to turn on the air conditioning led to Jake and Rosa missing a valuable clue that allowed them to solve the case.
- Not So Different: Rosa chastises Jake for promising the victim's mother that they would find the killer because she reminded him of his own mother. Later, Rosa does the exact same thing because the fact that the mother had lost touch with her son years ago reminded Rosa of her strained relationship with her mother after she came out.
- Poor, Predictable Rock: Jake always picks paper, even when he's playing against Rosa to prove that he doesn't always pick paper. He thinks he's using reverse psychology, but she's onto him.
- Red Herring: Invoked by the killer; he spread bags of other peoples' blood around the victim's apartment to make it look like there were more people there, and to throw off the police.
- Rule of Three: Parodied; Jake deliriously theorizes that the number three is important to solving the case because of three bloodstains, three veggie wraps, and... the tax on the wraps coming up to $3.19.
- Running Gag: Rosa has a different haircut for each scene, with Jake making a joke about it.
- Sanity Slippage: Jake begins to lose it due to the difficulty of the case and his emotional investment.