History Series / TwentyOneJumpStreet

** ''Shirts and Skins'': Penhall investigates the murder of a neo-Nazi leader with an adult son [[spoiler:who is eventually revealed as the killer]], while Hoffs and Ioki blend in with anti-racism vigilantes.

* ChekovsGun: there's a rather clever one in season 5's "In the Name of Love". In the first act, Mac visits the home of Lisa, the teenage girl he's been assigned to befriend (her father is the episode's BigBad). During an awkward attempt at seduction, Lisa mentions that she's always wondered what it would feel like to make love on her father's black leopard skin rug. Late in the third act, the investigation is going nowhere and Mac's being pressured to think of anything the police and FBI can use to get a search warrant for the house and warehouse. He remembers the black leopard skin rug, and double-checks that black leopards are endangered... and isn't it a felony to import endangered animals or products thereof? [[spoiler:It is. And it works.]]

* SomethingCompletelyDifferent: The episode ''Mike's POV'' is told entirely from the perspective of a high school student named Mike who is paid by a teacher to assassinate his wife. The Jump Street members appear to be regular students to him.
* StalkerWithACrush: ''Don't Pet the Teacher'': A female, pretty young and attractive, teacher at a high school is stalked by continuously getting love notes and unwanted presents by an unknown admirer. At first she and the police suspect it's one of her high school students [[spoiler:but turns out it's the school's janitor]].

* AdultsDressedAsChildren: More adults dressed as teenagers; the whole premise of the show is young looking police officers going undercover in high schools.

* AscendedFanboy: meta version for Johnny Depp. From his earliest interviews, he's stated his admiration for Charlie Chaplin and especially Buster Keaton. In the RashomonStyle episode ''How I saved the Senator'', Hanson's 'movie' is a silent film in the style of Buster Keaton. This was apparently at Depp's suggestion/request.
* BabysittingEpisode: Doug has a crush on his neighbour, who is a single mum; he hopes to go out on a date with her, but instead she asks him to babysit her baby, which he isn't enthusiastic about, but he does it.

* BowlingForRatings: Hanson is an avid bowler, and a few episodes feature shots of him in bowling alleys.

* ChuckCunninghamSyndrome: Hanson and Ioki's departures between Seasons 4 and 5 are never explained.

* ChekovsGun: there's a rather clever one in season 5's ''In the Name of Love''. In the first act, Mac visits the home of Lisa, the teenage girl he's been assigned to befriend (her father is the episode's BigBad). During an awkward attempt at seduction, Lisa mentions that she's always wondered what it would feel like to make love on her father's black leopard skin rug. Late in the third act, the investigation is going nowhere and Mac's being pressured to think of anything the police and FBI can use to get a search warrant for the house and warehouse. He remembers the black leopard skin rug, and double-checks that black leopards are endangered... and isn't it a felony to import endangered animals or products thereof? [[spoiler: it is. And it works.]]

* ClipShow: "Back From the Future" uses a young cop 50 years in the future, interviewing the now elderly members of Jump Street about their glory days, as a framing device for showing scenes from earlier in the series again.

* CompulsorySchoolAge: The cops are still adult age, but they look like high schoolers, so they have to go to high school to fight crime that happens in / around high school.

** Penhall comes across a group of these near the end of Season 4, when he's temporarily assigned back to uniform; the only innocent member of the group, besides Doug himself, is the rookie. [[spoiler: When Penhall turns them in, he recruits said rookie into Jump Street. Dean Garrett was the show's first attempt at a SuspiciouslySimilarSubstitute for Hanson; he sticks around several episodes at the murky end of Season 4 / beginning of Season 5 before disappearing, only to be BackForTheDead halfway through Season 5.]]

** Suverted for Booker. In the 1st episode he appears in, he physically bullies high school students as well as fellow undercover cops, and he acts racist, leading Hanson (and at first, the audience) to believe Booker is a Corrupt Cop. Turns out that Booker is an Internal Affairs officer though, so he was playing that role to provoke the Jump Street team. [[spoiler: He ends up joining the Jump Street team by the end of the episode, and isn't hinted as being a corrupt cop again during the rest of his appearances]]].

* CoolCar :
** Hanson drives a Sixties-era Ford Mustang.
** Hoffs drives a hip car--as remarked by the other characters In Universe in the Pilot. Hanson even keeps repeating "Really?" when she says it's hers, upon which she says in a fake-snotty manner "You know, they were all out of pink Cadillac's".
** Penhall drives a jeep-like vehicle, that another character ''really'' likes and keeps insisting on buying (Penhall: "It's not for sale.")

* CurseCutShort: In an OOCIsSeriousBusiness moment, the normally very composed Captain Fuller is about to say some choice words to an FBI officer who really irritates him, but doesn't get to it:
--->'''Fuller:''' Why don't you ''take'' that walkie-talkie and ''sh''--''[Is cut off]''

** Ioki goes through this at the end of "Things we said today", when he learns that a teenage boy's life took a turn for the disastrous mostly due to Ioki's unwitting influence: [[spoiler: Ioki accidentally convinces him to turn in his parents for drug possession; when they are sent to jail, the straight A, college-bound teenager goes on the streets rather than foster care or his Bible-thumping 'total bitch' aunt - when he's being arraigned for holding Ioki at gunpoint, Ioki tries to plead with the judge for extenuating circumstances, but the judge won't listen and the boy himself fatalistically accepts the outcome.]]

* RoadTripPlot: "A.W.O.L." starts out as this, as Hanson and Penhall have to transport a military guy who dodged service. About halfway through though, [[spoiler:the military guy escapes and Hanson and Penhall are lost and stuck in the wilderness and the cold]].

* ''Film at eleven'' plays with this; Mac is assigned to investigate the disappearance of a teenage girl, but he does so openly as a police officer; he doesn't go undercover, or anywhere near the girl's school.

** The biggest disgression happens with two episodes in Season 4, which respectively center around: first going to Florida on Spring Break, and then going to war-ridden El Salvador and discovering [[spoiler:Penhall's wife has been murdered by the corrupt military.]]

** Played with for Tony 'Mac' [=McCann=], Hanson's SuspiciouslySimilarSubstitute; in his case, it's more Manic Pixie ''Nightmare'' Girl, as she turns out to be the leader of a Satanic coven, which among other nasty things [[spoiler: practises human sacrifices of homeless people.]]

** "Whose Choice Is It Anyway?": A boy whose pregnant teenage girlfriend wants to get an abortion while he wants to have the baby, bombs the abortion clinic--but the girlfriend is there at the time, leading to her miscarrying the baby and her getting severely wounded. Upon finding that out, he has this reaction. Also see Laser Guided Karma.

** ''Hell Week'': a college student is raped at a fraternity party, in front of many onlooking other students. It traumatizes her so much that she quits college, and it also affects the life of her brother, who also is in that college.

* HeroicBSOD: Tom is so traumatized by his girlfriend's murder in "Orpheus 3.3", that he can do nothing but watch the security tape on repeat and attempt to do various pointless tasks within 3.3 seconds, the amount of time he believes he had to save her.

** ''Don't Stretch the Rainbow'' was mainly about racial tensions at a high school and a relationship between a black girl and a white boy there (that they had to keep secret to avoid escalation of the racial tensions). The girl turns out to be pregnant, and she and the boy together tell the whole school not only about their relationship, but that they are also going to raise this baby together, no matter what, and that the other students should take this as an inspiration to stop the racial hate. Their message does seem to make an impact.
** ''Whose Choice Is It Anyway'' featured this prominently, since it was about pregnant teenagers considering whether they should get an abortion, against the backdrop story of violence against abortion clinics. There was one pregnant girl in particular that Judy befriended.
* ThatCameOutWrong: Judy and Doug, both acting impulsively, [[spoiler:make out and even almost have sex]]. Afterwards, Judy feels awkward about it and then accuses Doug of [[spoiler:deliberately having tried to seduce her--her reasoning being "you had a condom with you"]]--which might make her a hypocrite [[note]]Keep in mind that this happened at a time Aids was still a death sentence, and that Judy had already unintentionally gotten pregnant once before at 17.[[/note]], but Doug's answer to that [[NotHelpingYourCase doesn't help his case]]: he blurts out that he ''always'' has condoms with him ''just like you always have a spare tire in your car in case your car breaks down''. Causing Judy to answer "O great, so I am a road accident?!"

** ''Whose Choice Is It Anyway?'' is about abortion, and violence against abortion clinics.
** ''The Girl Next Door'' revisited the topic of HIV. This example is particularly interesting, because it also showed how treatment (see Science Marches On on Trivia Page) and some attitudes towards HIV had advanced, even during the 2 or 3 years between the episodes.
* WhamEpisode: Season 4 ep. 4 ''Come From The Shadows'': Doug, who previously in the series had only had a serious relationship with Dorothy but otherwise was always pretty much a flirt with all women [[note]]including that he almost slept with his co-worker Judy[[/note]], falls seriously in love with and marries an El Salvadorian woman. She is extradited out of the U.S. by the end of the episode and in a WhatHappenedToTheMouse manner, isn't mentioned in any way for 14 episodes; then ep. 18 ''La Bizca'', another WhamEpisode, shows Doug and Tom going to war-ridden El Salvador to look for her [[labelnote:spoiler]]only to find out she has been murdered, but at least this gives Doug some closure.[[/labelnote]] For the remainder of the season, her entire existance is again ignored (though Doug adopts and cares for her nefew Clavo).

** Then there's Lisa Burbank, in ''In The Name of Love''; she's an outcast at school because of her HollywoodNerd image, plus rumors that her father's a criminal--which she fiercely denies. [[spoiler: But when she's visiting her father at his business warehouse, it's raided by the FBI & police--and she recognises one of the officers in the raid as the new kid at school... the cute guy who became her first friend in years, and who she even asked to have sex with her! Then undeniable proof is found that the father she's so loyally defended is a drug smuggler, and very likely guilty of everything he's been accused of (and the viewer knows that he's guilty of at least one murder)... and the only person willing to comfort her is said undercover cop, who pulls her into a tear-stained CoolDownHug as her father is led away in handcuffs.]]

* YourCheatingHeart:
** ''What About Love'': Judy Hoffs starts a romance with a man. Turns out he is married and deliberately concealed that fact to her. She brakes it off, only for him to turn into a StalkerWithACrush. Also an OfficeRomance gone bad, as he, in retaliation to her breaking the romance off, lies on a report he has to write about her and the Jump Street team.
** In an episode Judy's mother shows up, turns out she cheated on her husband / Judy's father. They get back together in the end though.

* StargateCity: Filmed in Vancouver.

** "Honor Bound": Does one of the murderers of the gay man, urged by Hanson and Penhall to confess, in the end confess, so that justice is served?

* DisguisedInDrag:
** Hanson had to disguise himself as a woman during a case where a boy was abducted and Hanson had to pose as the child's mother.
** Ioki put himself in drag when the team was trying to capture a man that was exposing himself to women.

** "Honor Bound": Some members of a military high school do violent assaults on gay men; one of the attacked gay men dies. The murderers don't have any remorse initially, but it turns out the murdered man is the boyfriend of one of the assailants' brother. Upon hearing that he murdered his brother's lover, the assailant is shocked, cracks and for the first time seems to consider gay people as ''persons''.

* OfficeRomance:
** Downplayed with Hanson and Jackie. He's a cop and she's a D.A., so they don't literally share the same office, but they often work on the same cases, thus knowing each other from work. Indirectly, they meet because their work overlaps (Penhall works with her, and is the one who sets them up); they also bicker about their common work environment (ep. ''Blue Flue''), and work eventually is what breaks their relationship (Hanson confidentially tells her something about a police case, but she tells the mayor, whom she works with as a D.A., leading to the case being dismissed; Hanson can't forgive her for that).
** PlayedForDrama with Judy. She starts a romance with a sort-of co-worker (a municipal employee who has to review the Jump Street officers). Turns out he's married and deliberately concealed that fact to her; upon which she breaks up with him. Then he turns into a StalkerWithACrush, stalking her with telephone calls and, when she refuses to continue the romance with him, outright lying on his report about her / the Jump Street program. This case is also [[ConversedTrope conversed]] In Universe, as Judy's story, once Hanson finds out, gets Hanson and Jackie (themselves in an OfficeRomance, see above) talking about {{OfficeRomance}}s, their viability and dangers.

* RewatchBonus: The opening scene of "Higher Education" shows a teacher interacting with a girl of his class, Patti. The teacher seems casual and nice towards her, and he to be a popular teacher with the whole class. Later it turns out that he [[spoiler:had coerced another student, Joy, into sex and gotten her pregnant after which he didn't want anything to do with her anymore; plus he probably slept with other female students too]]. Knowing that and watching the opening scene again, you realize he's actually subtly flirting with Patti. FridgeHorror especially sets in when you realize Patti later is shown to be tutored by him at his own house, and that's precisely how [[spoiler:Joy had gotten raped and pregnant]]--Patti was probably next...

* StalkerWithACrush:
** ''Don't Pet the Teacher'': A female, pretty young and attractive, teacher at a high school is stalked by continuously getting love notes and unwanted presents by an unknown admirer. At first she and the police suspect it's one of her high school students [[spoiler:but turns out it's the school's janitor]].
** ''What About Love'': Judy starts a romance with a man; when she finds out he actually is married and deliberately concealed that fact to her, she breaks it off. Upon which he turns into a stalker--keeping calling her despite her wishes, lying on a report he has to file about her / the Jump Street team, blackmailing her...

* TeacherStudentRomance:
** Played with with Johnny Depp's character, who is in his [[OlderThanTheyLook mid-twenties]] and not ''actually'' a student, but met and flirted with a woman just before he was actually assigned to her school and discovered she was now his teacher. For bonus points, this happens in an episode that frequently mentions Music/VanHalen.
** ''Higher Education'': A teenage girl tries to hide her relationship with a teacher by blaming her pregnancy on the now-disappeared boy she went to a school dance with: Ioki, undercover. [[ChocolateBaby Considering that both the student and teacher were white, if she'd had the baby it would probably have been evident that Ioki was not the father]].

** ''Higher Education'' had a teenage girl that got pregnant by her school teacher [[spoiler: it then turned out to be date rape]].

** "Last Chance High": Was Frances really physically abused by her parents, or was she making all of that up being at best delusional, at worst a pathological liar?

** "Eternal Flame": The person who turns out to be the bad guy, fraud and criminal, [[spoiler:is arrested for it; and his wife, whom he deceived and lied to, dumps him, which he most people would argue, deserves]]. It ends with a Tearjerker for [[spoiler:Hanson though, as he almost gets the girl (whom he speaks of as the love of his life), but she, at the end, abruptly says to him she wants to start a new life elsewhere, and leaves]].

** Ioki as a character gets much less attention than Hanson and Penhall, but gets the Season 2 episode "Christmas in Saigon" entirely, and the Season 3 episode "The Dragon and the Angel" mostly, devoted to him.

** Fuller's son, between the two episodes he appears in: first, he's a teenager who has become a Rastafarian and is acting like a hippie (this is played as "a teenager trying to find his identity") and has dreadlocks. In the other episode, three seasons later, he's an ambitious and almost preppy college student--and he's cut his hair short.

** Hanson's ex-girlfriend Linda he runs into in Season 4; she is an aspiring painter / artist, married to a nightclub owner (as admitted by herself, mostly because this man has the financial means to get her her own gallery). The attraction between this wacky character and the straight-laced cop Hanson is, is hard to explain, but it's probably "for old time's sake" only. At the end of the episode, she does a ScrewThisImOutOfHere, leaving town and leaving ''both'' her husband and a heartbroken Hanson behind [[note]]She is never mentioned again in the series, but, whether tellingly or not, in contrast to Seasons 2 and 3 in which Hanson had a girlfriend in Amy and Jackie respectively, Hanson's character never finds romance again during the series[[/note]].

** "Eternal Flame": Hanson encounters an ex-girlfriend (by now married to someone else) and relives romance with her; [[spoiler:at first the romance seems to be played straight / real, but at the end, even though Hanson goes straight for her, she denounces ''both'' her husband and Hanson, says she "needs to choose herself", and leaves town]].

** ''Last Chance High'' subverted this. Hanson meets teenager Frances who shows him her baby. When he asks around at her school about "when [Frances] was pregnant", they reply "Uh no, Frances ''never'' was pregnant...". [[spoiler:Turns out the baby is not Frances' daughter, but her baby sister whom she kidnapped from her own parents]].

** ''Best Years of Your Life'' is about suicide among teenagers.

** A criminal guy who gets a death sentence (in an interesting twist, earlier in the series he's featured as a pretty much one-dimensional criminal; by the 4th Season, he ends up getting the death sentence for his murders and a whole episode is devoted to showing his backstory, drawing some sympathy from the viewer).

** ''Eternal Flame'': Hanson runs into an ex-girlfriend, Linda, who's now married. That doesn't stop Linda from sleeping with and dating Hanson. Hanson and her are unaware that her husband actually knows of their affair, and it ends with [[spoiler:the husband attacking Hanson with a gun as a retaliation for Linda's cheating on him with Hanson; after which the husband is overmastered and arrested for his selling drugs, and shipped off; and Linda then [[ScrewThisImOutOfHere leaves town and]] ''both'' her husband and ex Hanson]].

* AgentScully:
** Hanson is totally skeptical of Penhall's claims that he encountered aliens (and this story is soon revealed to have a different explanation); and he's the one who doesn't believe the "medium" the team hires in "Old Haunts in the New Age" really channels the spirits of the dead, and quickly exposes him as a fraud.
** Also Captain Fuller, when the team starts to use ouija boards and hire spirit-channeling mediums, is very disbelieving of this, and basically calls the rest of the team idiots for hiring/believing the medium.

* SpookySeance: After a skeleton is found in the Jump Street chapel, the team (except for Hanson) use an ouija board and hire a medium, who supposedly channels the spirit of the dead body. He [[spoiler:quickly is exposed by Hanson as fraud though]].

** ''2245'' is about a man getting the death penalty.

* WhatDoesSheSeeInHim: Not a romantic, but a platonic and same-sex example. In Universe, other characters (a.o. Penhall, Fuller and the Sheriff) repeatedly wonder how on earth Russell Buckins can be Hanson's friend. Russell is a polar opposite from Hanson--reckless, impulsive and wacky--and the other characters worry because under the influence of Russell, Hanson, totally out-of-character, neglects his job and even does unlawful things.

* MaybeMagicMaybeMundane: The 'psychic' girl in "Old Haunts in the New Age". She sees / draws things that she shouldn't have any way to know, but she's not infallible either. Psychic, or lucky guess?
* MistakenForAliens: "Old Haunts in the New Age": Doug is convinced he has encountered aliens, and that they moved his belly button. [[spoiler:Turns out the lights he saw was just an advertisement by normal humans, not aliens]].

* ChristmasEpisode: Set against the backdrop of Christmas, "Christmas in Saigon" is about the police finding out that Ioki has been lying about his identity. It has flashbacks taking place in '70s Vietnam, but in present time it is Chrismas, and at the end, all characters have a Christmas dinner together.

* {{Cliffhanger}}:
** The ending of Season 3. Hanson is [[spoiler:wrongly convicted and sent to prison for a murder he didn't commit]] and Ioki is [[spoiler:in coma and on the brink of death after being shot]]. Also, Booker and Penhall have fallen out with each other over [[spoiler:the former's arresting Hanson, and the latter's lying during testimony in court]].
** The ending of Season 2--the team are told that Jump Street will be dismantled, and they all find other jobs during the season finale. [[spoiler:Come Season 3, Jump Street is restarted]].

* NeverLearnedToRead:
** The relevantly-titled "Afterschool Special": An illiterate boy in a disadvantaged-neighborhood high school.
** "Say It Ain't So, Pete": An illiterate university student that got into university on an athletic scholarship.

* OutOfFocus: Most episodes tend to center around the one or two officers working a case, with the captain and the other characters only getting a few lines here and there, but Season 4's ''God Is a Bullet'' is notable for not featuring any scenes at the precinct, and Penhall and Hoffs being the only main characters who appear. Later in Season 4, an entire episode took place in El Salvador, and didn't feature any police work at all and no characters but Doug and Tom.

* RashomonStyle: In ''How I Saved the Senator'', a [[ExactlyWhatItSaysOnTheTin Senator was saved]] from a bomb explosion targeted at him during a speech. A journalist interrogates all Jump Street members, and gets vastly different and contradictory stories from everyone. They are all shown as films in different styles: Hanson's is a silent, black-and-white movie [[note]]Which coincidentally already showcased Creator/JohnnyDepp's talent for physical comedy for which he was later praised for his role in ''Film/BennyAndJoon''[[/note]], Ioki's a martial arts movie, Penhall's a James Bond-style movie, etc. In the end, it turns out [[spoiler:none of the stories was true and a student did most to get everybody away from the bomb]].

* RequiredSpinoffCrossover: ''Wheels And Deals: Part 2'':[[note]]"Part 1" was part of Bookers own spin-off series[[/note]] After Booker left the Jump Street team (In Universe) and got his own spin-off show (in Real Life), he returned a few episodes later to work with the team to catch the criminal ultimately responsible for the events that happened to Hanson and Ioki at the end of Season 3.
* RewatchBonus: The opening scene of ''Higher Education'' shows a teacher interacting with a girl of his class, Patti. The teacher seems casual and nice towards her, and he to be a popular teacher with the whole class. Later it turns out that he [[spoiler:had coerced another student, Joy, into sex and gotten her pregnant after which he didn't want anything to do with her anymore; plus he probably slept with other female students too]]. Knowing that and watching the opening scene again, you realize he's actually subtly flirting with Patti. FridgeHorror especially sets in when you realize Patti later is shown to be tutored by him at his own house, and that's precisely how [[spoiler:Joy had gotten raped and pregnant]]--Patti was probably next...
* RoadTripPlot: ''A.W.O.L.'' starts out as this, as Hanson and Penhall have to transport a military guy who dodged service. About halfway through though, [[spoiler:the military guy escapes and Hanson and Penhall are lost and stuck in the wilderness and the cold]].

** In the episode ''Woolly Bullies'', the main characters recount the bullies who have plagued them in their youth. When Doug Penhall recounts his particularly bitter memories of such a tormentor, a friend suggests he seek the bully out and confront him. However, when Penhall does just that by finding the bully's current home, he learns that the bully is now a pathetic unemployed loser with an unhappy marriage to a shrewish wife. Delighted at this turn of events, Penhall decides not to speak to him and returns home quietly gloating how he got the classic best revenge by living well.

** ''Eternal Flame'': Hanson encounters an ex-girlfriend (by now married to someone else) and relives romance with her; [[spoiler:at first the romance seems to be played straight / real, but at the end, even though Hanson goes straight for her, she denounces ''both'' her husband and Hanson, says she "needs to choose herself", and leaves town]].

** Early in the series, Ronnie Seebok is a criminal who crosses paths with Hanson. In Season 4, we see more of his background and follow his (downer) fate: he's on death row and reaches out to Hanson (who earlier in the series arrested him) for support.
** In ''Wheels and Deals'', the whole team goes after the man who ultimately was responsible for Hanson getting [[spoiler:wrongfully convicted for murder and Harry nearly dying]] nine episodes earlier in ''Draw the Line''.
* SeriesContinuityError: ''Things We Said Today'' has a minor one, at least if episodes are assumed to be set in the same year they aired. A flashback to the day of the Challenger Explosion in January 1986 shows Ioki working a case and the Jump Street squad commenting on Captain Fuller as if he were still new to the squad. The first episode of the series aired in April 1987; Captain Jenko was still in charge at that point and Hanson was just joining the squad.

** "2245" episode: Ronnie Seebok kills one of the 21 Jump Street officers; there isn't enough evidence to arrest or convict him for this though. Later, he gets a death sentence for for a murder he ''didn't'' actually commit (it was his girlfriend who had shot the convenience store employee, but he was convicted for it).

* DeathRow: "2245": A criminal's last days, and past story, before he gets the death sentence are shown.

* DudeNotFunny: Both played straight and inverted in "Blackout", when Hanson, while undercover at a high school, plays a prank on two other students where he briefly fakes having cut off his fingers. The other students find it ActuallyPrettyFunny, but the teacher absolutely doesn't:
-->'''Teacher:''' ''[Annoyed]'' Do you think that's funny?!
-->'''Other students:''' ''[Laughing, and nodding their heads]'' Yeah.
-->'''Teacher:''' Maybe it'll be funnier in detention hall.

* NonIndicativeTitle: Though many episodes were named ExactlyWhatItSaysOnTheTin, there also were some with puzzling names.
** ''2245'' is a VerySpecialEpisode about a prisoner who gets the death sentence. That number doesn't appear anywhere in the episode, and fans have always been wondering what its significance is.
** ''Say It Ain't So, Pete'' is about gambling college students. There isn't any ''Pete'' character in the episode, and that phrase isn't uttered or referenced in any way in the episode.

* OverlyLongTitle: Season 4's episode "Awomp-Bomp-Aloobomb, Aloop Bamboom go Awomp-Bomp-Aloobomb, Aloop Bamboom".

** ''2245'': Takes (mostly) place in a prison, where it follows a man convicted to the death penalty.

* RelationshipRevolvingDoor: Douglas and his girlfriend Dorothy break up a few times during the series, and Penhall says about her:
-->'''Penhall:''' I've been with her for [a decade], but never any longer than 6 months at a time.

* BreatherEpisode: In Season 4, "Awomp-Bomp-Aloobomp-Aloop-Bamboom" (ep. 18) takes place in Florida during Spring Break and features partying college students and lots of girls in bikinis; this follows after episodes dealing with the death penalty and with illiteracy and college sports corruption, and following it comes arguably the most grim episode of the entire series, "La Bizca", which is about the civil war in El Salvador.

** Judy Hoffs was the female version. As Penhall remarks at a certain point, it doesn't say anything about Booker that he's flirting with Judy because "''everybody'' always flirts with Judy!". This character trait of Judy's was sometimes exploited when she played the DirtyHarriet.

* {{Fingore}}:
** Subverted / downplayed in "Blackout". Hanson seemingly cuts off three of his fingers while he's operating machinery; but then it's revealed this is a prank he plays on some other students, and he still got all of his fingers attached. His fingers ''are'' covered in blood though, so he did at least cut himself.
** Played straight and for drama when a student buys a cheap gun from the black market, and it malfunctions and explodes in his hand; his entire hand is severely injured.

* ShooOutTheNewGuy: Booker, who is [[CoolPeopleRebelAgainstAuthority totally rad]] and [[JerkWithAHeartOfGold a good guy deep down]], but is [[{{Badbutt}} kinda dangerous]] and [[CowboyCop plays by his own rules]]. Like, ''totally''.

* VacationEpisode:
** ''Awomp-Bomp'' [[note]][[Full title actually Awomp-Bomp-Aloobomb, Aloop Bamboom go Awomp-Bomp-Aloobomb, Aloop Bamboom[[/note]]: Although Hanson and Penhall go to Florida on a police assignment, it happens during Spring Break, so it has a vacation atmosphere.
** A very grim version is ''La Bizca'', in which Penhall and Hanson go to war-ridden El Salvador and find out [[spoiler:Penhall's wife is dead]].

* ByTheBookCop:
** Captain Fuller was this straight. He's strict about following procedure and expects his Officers to do the same, scolding or even suspending them when they do otherwise.
** Subverted for Officer Tom Hanson. He is strict by-the-book during the pilot episodes, but loosens up--sometimes purposely withholding information from Fuller, and one time even breaking into fellow Officer Booker's apartment to get evidence.
** Double subverted for Officer Booker. He first seems an inversion of this: he goes way over the line doing pranks on suspects, and acts racist. Then it turns out [[spoiler:that was a role he played because he is Internal Affairs, and he is trying to provoke the Jump Street team into unacceptable behavior]].

* DisappearedDad:
** Hanson's backstory, as his father died on the job as a police officer when Hanson was 16; his father apparently was a big inspiration for Hanson to chose to become a police officer.
** Many of the teens the team works with are also without Dads ([[MissingMom or moms]]). Most notably Quincy, the girl who acts reckless in "Out of Control"--her having lost her Dad is explained to be the main reason for her behavior, and she bonds with Hanson over losing a Dad as a teen.

* DaChief: After Capt. Jenko is killed off, Capt. Fuller takes over and makes it very clear from the beginning that he means business and giving him any lip is a ''bad'' idea.
* DroppedABridgeOnHim: Captain Jenko, WeHardlyKnewYe.

* FairCop:
** Tom Hanson was the male version. As his colleagues Hoffs and Penhall remark in "Back from the Future", the ladies really noticed him. And he was played by Creator/JohnnyDepp, who was the shows MrFanservice.
** "In the Name of Love" referenced this for Hanson's Season 5 SuspiciouslySimilarSubstitute Tony [=McCann=], only in a negative fashion. The FBI agent they're working with refers to the 21 Jump street 'studs', in a tone of voice full of UnfortunateImplications. Mac and Capt Fuller are both clearly offended by the implications in the agent's tone, but they can't protest too much because they have to work with the man on an important case.

* HenpeckedHusband: Despite not actually being married, Penhall gets a bad case of this when Dorothy rather abruptly decides to not only get back together with him, but also to move in with him (uninvited). Cue every nagging housewife cliche the writers can think of. Taken Up To Eleven when Dorothy ''throws Penhall out of the house'' they just bought together, forcing him to beg his friends to give him a place to stay.

* HiddenHeartOfGold: Captain Fuller, when he showed up to replace Captain Jenko in Season 1 ep. 6, was played as a very stern, strict man and police Captain--essentially the opposite of the Hippie, rocker Captain Jenko. Fuller remained a very strict and by-the-book Captain for the police officers, but throughout the series little bits of background about the man were unfolded that made you feel for him--especially, that he was hurt very much by having his son taken away out of his life after a divorce after he cheated on his wife with a police co-worker (something he confessed to his police subordinates in a Season 2 Valentine episode, and which he still was regretful about). He also despite his strictness ''was'' willing to come through for his officers when push came to shove--most notably, in Season 3 ep. 1 when Hanson suspects something is off about Booker, Fuller pulls some strings to find out Booker is from Internal Affairs.

* NewAgeRetroHippie: Captain Jenko, an aging hippie who, in the first episode, has to teach Hanson how to act like a bad seed.

* RedOniBlueOni:
** Penhall and his (most-of-the-time) partner, and best friend, Hanson, respectively. Penhall was more brash, Hanson more by-the-book.
** When Penhall was living in Ioki's apartment during Season 3, Penhall was the Red Oni to Ioki's Blue Oni; Ioki was shown to be very precise in keeping his house neat and clean, and Penhall was shown to be messy, which caused friction between them.

* SadClown: Penhall. He acts all brawny but as the show progresses, we learn that he has a tragic backstory--including [[spoiler:that his mother committed suicide when he was six years old, and that he's estranged from his brother.]]

* EndOfSeriesAwareness:
** Season 2 ends with the Jump Street program being suspended, possibly due to the writers not knowing if the show itself would be canned or get a third season.
** Hanson makes several references to wanting to quit the force in Season 4. It was well known by this point that Johnny Depp wanted to leave the show, which he actually did at the end of the season.

* ArtisticLicenseLaw: "Higher Education": A high school teacher confesses having raped a teenage student of his... while the girl's father threatens him with a baseball bat and officer Ioki stands by and does nothing. As much as this teacher is an abusive bastard that the viewer wants justice served upon, a confession obtained this way wouldn't hold up in court.
* AssholeVictim:
** The ShockJock whose car gets blown up in "Next Victim". Due to his hateful and racist ranting, the team is none too happy about having to look for the person who did it.
** Character Booker was written out of the show after lasting only one season; ironically, his character was shipped off due to doing the ''right'' thing (uncovering that Hanson was sent to prison innocently), but due to Booker being antagonistic to Hanson (the most popular character--hey, it is / was Creator/JohnnyDepp) from his first appearance on, and to Booker seeming ambiguously racist, Booker can easily be taken for an Asshole.

* DrivenToSuicide: "Best Years of Your Life": A teenager commits suicide after being arrested.

* DudeNotFunny:
** In "Best Years of Our Lives", this is pretty much everyone's in-universe reaction to Penhall when he starts telling incredibly crass jokes about suicide as a coping mechanism to deal with a student killing himself [[spoiler:(and, as it turns out, his own mother doing the same back when he was just six)]].
** Both played straight and inverted in "Blackout", when Hanson, while undercover at a high school, plays a prank on two other students where he briefly fakes having cut off his fingers. The other students find it ActuallyPrettyFunny, but the teacher absolutely doesn't: