- Alternate Character Interpretation:
- The grey hero of the series, DCI Luther. True Cowboy Cop who is on the edge and will stop at nothing to make sure that the worst of the worst are stopped? Or is he a burnt out cop unable to feel for the victims driven to win by his sense of self worth? A man so apathetic to all the horror that the only person he can relate to is a cold-hearted killer.
- Alice Morgan, a cynical genius whose outlook on the Universe — how everything and anything can be rendered into pointless nothing — led her to murder her parents after years of hidden resentment. Or a brilliant young woman shaped by being seen yet unseen who relishes her time with Luther as he knows her real self. And will do anything to help the closest thing she has to a friend. Including, as of episode four, Murder Henry Madsen.
- Ian Reed's skill at psychological manipulation makes it very hard to tell whether he had always secretly been spiteful and amoral, or whether he was a decent guy who was tempted by the promise of easy money, panicked and behaved like a coward when things went wrong, and then pretended to lack remorse as a way to troll Luther into putting him out of his misery.
- Award Snub: Despite massive acclaim Idris Elba has never won an Emmy for playing Luther, even with being nominated for the first four seasons. However he did get a Golden Globe and a SAG award, so that softens the blow a bit.
- Awesome Music: The title theme "Paradise Circus" by Massive Attack, and happens to be a pretty good summation of Luther's character.
- Bat Deduction: Some of Luther's detective work is arguably just guesses that happen to be right.
- Complete Monster:
- Terry Lynch, from the second episode, is an ex-military officer who was thrown in prison for murdering a police officer in a scuffle. Upon being denied parole, Lynch gives his abused son Owen plans and schemes to act out in a quest for both freedom and revenge. Having Owen begin systematically murdering police officers around the city, including sniping and bombing them, Lynch ultimately gets more than a dozen officers killed and injured. Lynch hopes to get a reduced sentence in exchange for stopping his son, revealing Owen has been instructed to continue killing until Lynch says stop, and when confronted by the possibility of Owen dying, Lynch simply laughs and reveals he doesn't care about his son, only his freedom.
- Cameron Pell, from season 2's first two episodes, is a failed artist who admires the likes of Jack the Ripper and Spring-heeled Jack for the fear and infamy they've amassed over the centuries. Wanting that same fame for himself, Pell dons a mask and begins murdering innocent people by strangling them and slashing their throats open. After failing to kill DCI John Luther, Pell kidnaps the man's partner, DS Justin Ripley, and subjects him to brutal torture that he broadcasts to the entire police station. Pell's master plan is to murder over a dozen schoolchildren, dissolve their bodies, and ship the corpses out of the country, leaving the parents of the children forever in agony at never knowing what happened to their kids, and cementing Pell into London's most monstrous of villains.
- William Carney, from season 3's second episode, is a particularly vicious Serial Killer and sexually violent criminal who killed many women several years ago, starting with middle-class wives before moving onto prostitutes. After failing to kill two teenage girls and a mother, Carney was arrested and locked away. In the present, Carney manipulates Paul Ellis, the son of one of his victims, into carrying on his murders, sending the disturbed man after victims who got away from Carney in the past, resulting in many more brutal deaths. When confronted about his crimes, Carney can only laugh and reveals his crimes were committed just because he enjoyed them, and he attempts to make his final victim one of his own nurses simply because he hated being seen as "weak" by her.
- Evil Is Sexy: Alice Morgan can go from grieving daughter to flirtatious vamp at the drop of a hat.
- Foe Yay: Alice Morgan and Luther. The interrogation in which they first meet — mixing in scientific theory and relativity — sounds like good-natured flirting of two people on a first date.
Luther: Stay away from Zoe!
- Gets pushed to eleven in one of the final scenes of episode one. A confrontation on a bridge leads to Luther deflecting a knife from Alice and nearly choking her on the spot.
Alice: Kiss me, Kill me... do something.
Look at her, with her eyes like a flameShe will love you like a fly will never love you...
- The fact that they keep calling each other to taunt/flirt only adds to this.
- In episode three Alice and Luther admit they are scared of each other.
- Alice's reaction to Luther walking away when he declares he can't see her again in episode four sounds a bit like a lover scorned.Alice: No.
- In episode Six Alice finds Luther has broken into her flat. She thought he was an intruder and, armed with another sharp implement and wearing a nightie, says casually...Alice: If you wanted a key, all you had to do was ask.
- In the same scene Alice tells Luther that if he killed Zoe, he must have had a good reason. Luther then states that he didn't do it. Alice face-faults as if she was hoping he'd say the reason was her.
- In Series 2 Episode 2 Alice askes Luther to run away with her He says no
- Lampshaded also in the title sequence song.
- Fridge Logic: Why would Mark believe Luther's claim that he's innocent of Zoe's death, especially when he's working in cahoots with the woman who was behind him being beaten up?
- With Mark he had interacted with Luther enough to realize that a.) he did love Zoe and b.) if Luther was guilty he wouldn't waste time trying to lie to Mark.
- How the hell did Cameron Pell sneak into the backseat of Justin's police car without being noticed or, apparently, opening the door?
- When Gray and the ex-wife exit the car, we can see the dome light doesn't work.
- Genius Bonus: When Erin is pissed off at her colleagues in Episode 204, she quotes the last line from Animal Farm.
- Idiot Plot: Nearly everything about the end of series 1 with regards to Luther being framed for Zoe's murder and his attempts to clear his name. Reed tells the rest of the unit a story about Luther being responsible and trying to say Reed killed her instead. Rather than wait to see the evidence peacefully, everyone takes Reed's word for it and goes all in on believing that Luther's guilty. Luther, for his part, never tries to tell anybody about the incident with Reed killing the kidnapper Sugarman and how that escalated, (complete with the hotel security footage that would show both men were there and the maid who can testify that Luther saved her when another man tried to shoot her) never volunteers to have the record of his phone calls brought in as evidence, (which would beyond a doubt establish that Zoe called him right around the time she was killed, and possibly that he wasn't at the house at the time she was killed) never tells anyone to look in Reed's locker for the diamonds Reed stole, (which would be a good first step to blowing holes in Reed's story and at least implicate him for serious corruption that would require further investigation, which might help Luther) and doesn't even make a serious attempt to get Reed to implicate himself when the two meet in the park while under police surveillance. Instead he comes up with a cockamamie plan that involves convincing his ex-wife's new lover Mark that he's innocent, (instead of, y'know, trying to convince the police that he's innocent) having Mark break into Reed's locker to steal the diamonds, (again, instead of just telling his colleagues in the police that the diamonds are there) then trick Reed into following Mark to a spot where Luther and an armed and unhinged narcissist/sociopath, (whose behavior makes her a major wild card) Mark, and Luther can work together to trick Reed into incriminating himself on a recorder, which is far less convincing than Reed incriminating himself on a recording while under police surveillance. (Since Reed or a lawyer representing Reed can always try to argue later that Luther may have tampered with/altered the recording, or that Reed was simply humoring a man with a gun by saying anything he wanted to hear, both of which they couldn't say if Luther got Reed to do the exact same thing while the two are being watched by the police.) The whole situation, and Luther's "solution" to it is so dumb that it sounds like it comes from a particularly trashy Soap Opera.
- Nightmare Fuel: Many of the killers are Nightmare Fuel incarnate:
- In episode three of season 1 a satanist has a thing for writing in human blood. Thing is, he tends to write whole novels at a time.
- Cameron Pell wears a creepy Mr. Punch mask and kills people simply to become as feared as Spring-Heeled Jack, Jack the Ripper or any other infamous serial killer. His last act before he is stopped is to attempt to gas a busload of school children to death, put their bodies in acid and ship the acid containers around the world so they can never be found.
- The Milberry twins never say a word and attack people seemingly at random (actually a game they are playing using dice rolls.) The first twin is caught after stabbing a courier to death, stealing his outfit and storming an office, where he proceeds to hit the staff with a hammer and spray acid in their faces.
- Paul Ellis breaks into people's houses and is seemingly able to remain motionless for hours until they come home, at which point he goes berserk, possessing enough strength to suplex a grown man through a ceiling, all the while screaming like an animal. The worst part? He is only doing it because he's become enthralled to the man who killed his mother when he was a child.
- Steven Rose is a cannibal who eats people to take the qualities he perceives them to have that he does not. He is also an IT wizard who used his job as a repairman to spy on his intended victims. All 200 of them!
- Moral Event Horizon: Ian Reed crosses it when he kills Zoe. Vigilante Man Tom Marwood crosses it when he guns down Justin Ripley and right after attempts to kill Mary Day, proving his claims of protecting the innocent are so much garbage.
- They Wasted a Perfectly Good Plot/Character: George Stark is a retired policeman who, along with Gray, spends Season 3 trying to nail John Luther for being a dirty cop (which he isn't; as one character puts it he's "a cop who gets his hands dirty, not a dirty cop. There's a difference.") As Season 3 progresses it becomes more apparent that Stark is hell-bent on taking down Luther to the point of using Insane Troll Logic to paint him as guilty, and even Gray starts to doubt whether they're doing the right thing. All of this might make the viewer think that Stark is pursuing a personal vendetta against Luther (maybe he was a genuine dirty cop that Luther forced into "early retirement") and will be looking forward to the moment Luther shows him up for the petty, vindictive hypocrite he is. What happens instead? He is unceremoniously blown away by Tom Marwood, conveniently removing him as a problem and absolving Luther of any need to do anything to prove his innocence.
YMMV / Luther