Kommissar Gereon Rath
A vice detective, newly transferred to Berlin from Cologne to investigate a series of underground porn films involving high-level city and national officials. He fought at the tail end of World War I, serving briefly on the Western Front, while is older brother Anno went missing in action - his traumatic experiences at the front, as well as losing his brother, gave him severe PTSD that sometimes causes severe attacks, for which he takes a not-fully-described medication. Since the end of the war, he has been involved with his brother's widow, Helga, who has a son named Moritz.
- Anti-Hero: He is a drug fiend who willingly covers up powerful people's perverted behaviour, covers up the fact that he shot a guy by falsifying the evidence, lies in court to cover up his colleagues' violent behaviour for personal gain, leaves his injured brother to die on a battlefield in France (and covers that up as well) before seducing his brother's grieving widow.
- Cain and Abel: Gereon and Anno, respectively. Though he tries to hide it, Gereon feels spite for his late brother, in whose shadow he had endure living for most of his life. It becomes especially egregious when it's not only revealed that Gereon has started courting brother's widow, but actually left his injured brother to die on a WW1 battlefield.
- Cowboy Cop: While Bruno is a no-brainer, Gereon himself is one in a By The Book Cop's clothing from the get-go, what with being tasked on destroying evidence of sex crimes and going as far as breaking, entering and starting shootouts to get it done.
- Defective Detective: He's got a drug addiction, mad PTSD, and piles of guilt over what happened to his brother — not to mention his troubled personal life. He's still a damn good investigator and is responsible for solving many of the mysteries in the series.
- Functional Addict: He is hooked up on laudanum which was prescribed to him for his PTSD, yet he remains a very good detective.
- Hardboiled Detective
- Hidden Depths: Establishes that he's more than just a Defective Detective and Shell-Shocked Veteran in the first episode, when he displays impressive dancing skills and even attempts running up a wall. Had Gereon not gone to war, he might be a much different person.
- Old Cop, Young Cop: Is paired with the much older Bruno.
- Parental Favoritism: Always played second fiddle to his elder brother Anno, who was more or less his parents' favourite child. Needless to say that, when Anno went MIA in the war, it made Gereon's life as the surviving child hardly any easier than before.To [my mother], the wrong son came home.
- Parental Substitute: For his nephew Moritz, as his brother has been missing since World War I.
- Real Men Love Jesus: Is a devout Catholic.
- Shellshocked Veteran: As a veteran of the Great War, he suffers PTSD much more than others and takes laudanum to combat their nervous seizures. He hides this fact from others due to social condemnation of "tremblers."
- Survivor Guilt: His brother died in the war, but he came back. In the last episode it seems like his brother might still be alive and might in fact be his therapist. Gereon is pretty out of it at that point, though.
- Your Cheating Heart: Has been in love with his brother's wife since before they were married. There is no reason to believe the affair started before said brother's death, though.
A flapper girl, waitress, and part-time prostitute who, largely by her own insistence, begins serving (off the record) as an assistant and informant to Rath and Wolter's investigation. She hails from the poverty-stricken slum of Wedding, and largely takes care of her younger sister since her family is too useless, abusive, or sick to do it. She also desires to be the first female homicide detective in Berlin.
- Amateur Sleuth: Manages to get a job as a typist for the homicide division. Promptly decides she wants to become a proper policewoman (still something of a rarity at the time), and departs on crime-solving capers that would get anyone else thrown in jail.
- Big Sister Instinct: Charlotte is very protective of her sister and insists that she should stay in school.
- Cool Big Sis: Is a positive role model for her youngest sister Toni.
- Dysfunctional Family
- Hooker with a Heart of Gold: Works as an unlicensed prostitute and she is one of the kindest characters on the show. Only does it to pay her family's bills (and it wasn't uncommon anyway for the time and place).
- Hyper-Competent Sidekick: Has shades of this, as she's officially just a typist but ends up finding quite a few of the clues.
- Naughty by Night: Charlotte's "night job" is work as a prostitute.
- Only Sane Man: Often seems to be this in her family.
- Sassy Secretary: Has shades of it.
Oberkommissar Bruno Wolter
Rath's senior partner and Deputy Chief Inspector of the vice squad. His jovial, boisterous personality hides a more steeled, calculating core. Like Rath, he was deeply affected by his war experiences, but seems, like many veterans, to long to return to the glory days of war with a strong Germany and firmly believes the stab-in-the-back myth. He also takes on Rath's nephew, Moritz, as a protege, teaching him how to shoot.
- Big Bad Friend: Turns out to be one of the central planners of the Black Reichswehr's coup d'etat. He was also behind the killing of Jänicke, and eventually attempted to ruthlessly murder both Charlotte and Gereon.
- Dirty Cop: Pockets a clip of cash that he finds at the pornography studio. Also takes payments from the Madam at the Moka Efti brothel.
- Dissonant Laughter: Whenever Bruno and Gereon get into a physical fight (which happens repeatedly), it usually ends with Bruno breaking into chuckles. By the end of Season 2, it has veered off into downright Giggling Villain territory.
- Even Evil Has Standards: Might be a murderer, an anti-democratic conspirator, a textbook example of a Dirty Cop and an all-round jerk, but acts as a cool uncle to Gereon's nephew, and even a surprisingly benign blackmailer-cum-suitor to Charlotte.
- Friend to All Children: Whenever we see him interacting with children on screen, he's genuinely friendly and encouraging towards them, despite his otherwise gruff personality. The fact that they're usually boys with a penchant for military stuff probably helps, though.
- Karmic Death: Dies in an explosion of the leaking tanker wagon when he lights a cigarette.
- Noble Bigot with a Badge: Is a caustic, crooked, sexist, lecherous and distrustful guy (with some pretty unsubtle spite for the Weimar democracy at that), but he a reasonably decent partner to Gereon.
- Old Cop, Young Cop: Gets paired with the much younger Gereon.
- Parental Substitute: Evolves into this for Moritz, Rath's nephew.
- Pet the Dog: Pays for Charlotte mother's cremation.
- Politically Incorrect Villain: Expresses casual sexism against Charlotte.
Councillor August Benda
A Jewish Social Democrat, member of the Berlin city council, and head of the Political Section of the Berlin Police. One of the few people who seems to wholeheartedly believe in the Weimar Republic and thoroughly disliked on all sides by Communists, Nazis, and monarchists.
- Cowboy Cop: He fundamentally has the interests of the Weimar Republic at heart, but he's not above underhanded tricks. He agrees to ignore the brutal murders of 15 Soviet dissidents in exchange for information about the Reichswehr's covert activities, and organizes the PR sham playing off a cop shot by his two year old son as a supposed victim of Communist violence.
- Reasonable Authority Figure: Benda is the liaison between the Weimar government and the Berlin police. He's a dogged defender of the democratic constitution against extremists of the far right and far left. Has an open ear for the protagonists and though he doesn't always agree with them, he always has reasons to do so.
A young and perceptive detective who begins a flirtation with Charlotte. He lives with his two deaf parents and his keen eyes and ability to read lips often give the police an edge when it comes to sensitive operations.
- Nice Guy: Is a kindhearted, polite chap.
- Sacrificial Lamb: Is killed in the second season to show what's at stake for the heroes.
The photographer of the Berlin Police.
- The Lab Rat: We see him several times developing photographs in his darkroom.
- Crossdresser: Gereon meets him as a Lady in Red drag queen at the Hollaender club.
The Chief of Police.
Generalmajor Kurt Seegers
An officer serving in the Reichswehr after its downsizing by the Treaty of Versailles. He is not happy with Germany's current state and makes no secret of his desire for a return to the old system. His funding of a rearmament program in violation of the Treaty is something of an open secret.
- Early-Bird Cameo: He appears quickly in the pilot signing for the train to pass the border. His proper introduction comes in later episodes when he learn he is part of the Black Reichswehr.
- Four Eyes, Zero Soul
- Politically Incorrect Villain: During interrogation, Seegers expresses his contempt for the Weimar constitution, followed with open anti-Semitism against Benda. At one point he asks Benda how one of (Benda's) kind could ever hope to claim to care for Germany's future. It's very obvious that Seegers is referring to Benda's Judaism (and thus insinuating that Benda is not, in fact, a true German) rather than anything else.
- Villain with Good Publicity: The public and the government generally approve of his secretive rearmament programs. It doesn't extend to an attempt at high treason, though.
Major von Beck
Seegers' subordinate and right-hand man.
- Good Scars, Evil Scars: Sports a prominent Dueling Scar on his cheek. These were popular among Prussian nobility in the 19th and early 20th centuries.
- Tyrant Takes the Helm: After Benda's death, Wendt replaces him and plans a massive reorganizing of the police force. He assigns Gereon to head up a new corruption division, but given his involvement in the Black Reichswehr's coup attempt and the fact that the sympathetic Hindenburg appointed him, his motives are by no means pure.
The Soviet ambassador. Stalin's government has charged him with hunting down Trotskyists and assisting German rearmament in exchange for military knowledge.
- Dirty Communists
- Photographic Memory: He claims to recognize Charlotte at the Moka Efti due to his photographic memory. Charlotte manages to bluff her way out.
A Russian socialite who performs as a singer named Nikoros. She is at the center of many of the series' varied criscrossing plotlines.
- Crossdresser: Performs in drag as the singer Nikoros.
- Fake Aristocrat: It's revealed that "Countess" Sorokina is merely posing as the heiress of a murdered noble family while she was only the daughter of the chauffeur.
- Femme Fatale Spy: Wastes no time selling out the entire Trotskyist Cell to Soviet agents (thus killing most of them) and getting away with it. Then she visits Nyssen. Nyssen attempts to furiously reject her, but is seduced once more by her charms.
- Sdrawkcab Alias: Her stage name "Nikoros" is "Sorokina" spelled backwards. Gereon realizes this after seeing her poster in the mirror, although nothing comes of it.
A Trotskyist revolutionary attempting to overthrow Stalin as the leader of the Soviet Union.
- Rebel Leader: Leader of the Berlin cell of Trotskyist revolutionaries.
- Russian Guy Suffers Most: Witnesses the brutal murder of everyone in his revolutionary group, swims through raw sewage, is stabbed by a vagrant, is chased naked through the streets of Berlin, falls onto a barge and dislocates his ankle, is betrayed and then shot at point-blank range by his former lover, has his ankle painfully set by a Morally Ambiguous Doctor, and nearly dies from inhaling phosgene gas. And he is alive and kicking at the end of Season 2 when he visits Sorokina in Paris.
An organized crime boss who appears to have a monopoly on Berlin's underworld. He takes opportunities as they come and always tries to twist it to his advantage.
- Blackmail: He keeps compromising film reels in his safe which he uses to blackmail public figures including the Lord Mayor of Cologne Dr. Konrad Adenauer.
- The Don: The parallels to Vito Corleone are obvious.
- Hand Signals: Gives orders predominantly via hand signals.
- Screw the Rules, I Have Connections!: Claims that he owns the Berlin Police.
The Armenian's right hand.
- Sinister Minister: He is the Armenian's mob enforcer who goes by the nickname "Saint Josef" (and may or may not actually be an ordained priest). He generally struts around town in a Catholic habit and biretta clutching a rosary, delivering threatening messages in the name of his Boss and Dr. Schmidt.
- Tattooed Crook: The fact that he is a criminal rather than a legitimate minister is revealed by the tattoos visible on his hands, and he's actually covered with tattoos.
- Good Scars, Evil Scars: Half of his face is covered in heavy scars which look like he was burned or seared.
- Herr Doktor: A German doctor with a common German name wearing metal rim glasses while using suggestive therapy on people.
- Morally Ambiguous Doctorate: Has been known to employ the services of "Saint Josef" and conduct his shellshock treatment experiments on a drugged and kidnapped Gereon. Then again, he later reveals himself to be Gereon's long-lost brother Anno, so Gereon might have just been an exception.
Gereon's temporary co-tenant. An Austrian reporter who emigrated to Berlin and works on exposés about right-wing conspiracies.
- Intrepid Reporter: Has been investigating the police cover story for the May Day riots involving the officer who was shot in the leg. He discovered that the officer's son was responsible for shooting him, accidentally. Later on the trolley, Gereon reads an alarmingly accurate story regarding the Black Reichswehr written by Katelbach.
- Funny Foreigner: Is an erudite, yet undeniably eccentric Austrian academic.
- Mr. Exposition: Explains the communist infighting to Gereon.
Gereon's land lady.
- Widow Woman: Reveals that she is a war widow. Often wears black dresses.
Gereon's long lost brother.
- Aloof Big Brother: Was this to Gereon. When Anno went MIA in the war while Gereon was the one who made it back home, their parents were supposedly very disappointed.
- Chekhov M.I.A.: We are told that he was injured and captured by the French in World War I, but nobody has heard from him since. In the last episode of Season 2, Dr. Schmidt reveals himself to Gereon as Anno and both embrace.
- Legally Dead: After he went MIA in WWI, he was officially declared dead in 1929, which meant that his wife Helga and Gereon could finally pursue an open relationship.
Dr. VoelckerA welfare doctor and district councilwoman for the Communist Party.
- Rabble Rouser: Returns (in the wake of the police gunning down two unarmed women) to rile up a demonstration right in front of the police headquarters.
Charlotte's little sister.
- Gender-Blender Name: Toni is foremost a male name.