These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation: The killer in "The Hen House" can be seen as either an attempted Atoner tragically pushed back into doing evil again, or simply a murdering, identity-stealing, Nazi scuzzball through-and-through.
Anvilicious: In "That Woman", we learn the important lesson that suggesting a group of teenagers exercise self-control will turn them all into heartless killers.
Josh Freely from season 1's "Fly Away" was the first and worst in what would become a long line of secondary villains more despicable than the actual killer. A social worker working with emotionally-ustable parents, he is in reality a brutal pedophile who uses his position to find new victims. Freely piles emotional abuse onto the parents, making them feel as though they're worthless, so they surrender their kids to him, and if that doesn't work he's more than happy to fudge his own records so his superiors order the children removed. His abuse eventually reaches the point that one such mother murders her daughter rather than let Freely take her.
The season 1 finale, "Lovers' Lane," brings us Jim Larkin, a slovenly glutton and serial rapist. Too lazy to even abduct victims himself, he instead badgers his abused and weak-willed son to do so for him, usually unattractive teenage girls he pretends to befriend. His assaults are absolutely brutal, reaching the point at which he murders one of his victims simply for calling him "disgusting." Oh, and he allowed an innocent man to rot in jail for 18 years because of his crime.
Roger Mulvaney, of season 3's "A Perfect Day," is without question the worst Domestic Abuser in the series. A Dirty Cop who ruthlessly beats his wife and two daughters, he eventually, once she decides to leave him for another man, resolves that if he can't have them, nobody could, kidnapping the three of them and making his wife watch as he throws one of the girls from a tall bridge.
Rayanne Leland from season 5's "Spiders" is a sugary-sweet stay-at-home mom who also happens to run a Neo-Nazi coven out of her basement. When her son Truitt murders a Hispanic woman, Truitt's girlfriend, Tamyra, turns to Rayanne for help, only to find to her horror that Rayanne wholeheartedly supports her son's actions, and calmly tells Tamyra that all Hispanics should be exterminated, her warm, loving smile never leaving her face. When Tamyra threatens to go to the police, Rayanne emotionally manipulates the most insecure and sympathetic member of the coven, Elliot, into beating her to death with a hammer.
John Smith from season 5's "The Road" is the most horrific Serial Killer seen on the show. Disturbed since childhood, he described the sight of watching a woman drown while doing nothing to save her as the most beautiful thing he'd ever seen, and dedicated his adult life to replicating that "beauty." Abducting women who were perfectly happy with their lives, Smith brought them to special cellars where he sealed them off, watching as they went insane from isolation before finally leaving them there to starve.
Daniel Patterson from season 5's "Slipping" is the ultimate gaslighter. Insanely jealous of his wife's skill at poetry, he hatched a plan to both steal her work for his own and get rid of her. With the aid of his slavishly-devoted (and not very intelligent) housekeeper, he did everything in his power to drive his wife insane and ultimately to suicide, maintaining his facade of a caring husband all the while. When she learned the truth and confronted him, he murdered her himself. To prevent his stepdaughter from knowing the truth he sent her to a notoriously harsh boarding school, believing his story that her mother committed suicide for 45 years. In doing so he not only made her fear that she would go crazy as well, but also that SHE was the one who had driven her mom over the edge. When Scotty and Vera call him out on it, he simply says "I was so desperate. People expected so much from me, I had NO CHOICE!!!!"
Harsher in Hindsight: "Late Returns" was based on the real-life murder of Chandra Levy, an intern to a Congressman whom she was also sleeping with. The public opinion of the time, as well as the episode, pointed the blame at the Congressman, and the scandal ruined his career. Several years after the episode aired, the Congressman was found to be completely innocent.
In "The Plan", the closing montage shows that the military academy's swim teacher is now a woman. Presumably she was hired because it's been revealed that the last teacher, a man, was a pedophile, but the recent rash of teacher/student sex cases means it isn't really any less likely that she isn't one herself.
Hollywood Homely: The main victim, Martha, in "Lonely Hearts." We're repeatedly told that she's extremely unattractive and has no chance with men, and even the detectives, in a surprising display of insensitivity, comment that her traditionally-handsome boyfriend "must've had some kind of fetish." In reality, while she's somewhat overweight and by no means supermodel-gorgeous, she comes across as an adorable Manic Pixie Dream Girl type apart from being an accomplice to a Serial Killer, that is and in the scene she first meets her lover she has a flower in her hair and is fairly pretty.
Also the victim's daughter and murderer in "Blackout," who is continually put down as "plain" by her drop-dead-gorgeous mother.
And the killer in "The Crossing", who's made out to be the dowdy, matronly alternative to the glamorous, willowy, red-headed victim—even though they're about the same age—simply because she's brown-haired, slightly plump, and dressing in drab clothes.
Hot Guy, Ugly Wife: The handsome lothario in "Lonely Hearts" liked to court unattractive women, mostly because he knew they were so desperate they'd put up with his crap and therefore be easy to scam. But when his latest victim calls him out and instead of turning him in, suggests working with him and ratcheting up their schemes to include murder,he seems downright turned on. When she herself is killed (not by him, ironically), he's so despondent that he never takes up with another partner and years later finally kills himself while watching a videotape that she made, implying that in his own bizarre way, he genuinely fell for her.
Ho Yay: The show has many acknowledged gay couples but "One Night" has an ambiguous relationship between Justin (who was almost a victim) and his friend Valentino that is often interpreted as this.
In "Jurisprudence," Doherty having Kat transferred, simply as Revenge by Proxy to spite Stillman.
Narm: In Andy in C Minor the tension between deaf and hearing people is about as bad as 1960s racial tension, complete with everyone trying to pull apart two lovers because they belong to different worlds, and the victim having been killed because he wanted to get a cochlear implant.
The one about the murdered horse jockey. It's hard to take it seriously when some of the people would flash back to them wearing those ridiculous jockey uniforms.
The most Crowning Music Of Awesome episodes are the ones where they feature a single artist. The episode featuring Bruce Springsteen's songs from each decade is the most awesome one.
Recycled Premise: Though the majority of the premises are different, many viewers online noted that the episodes Family and Almost Paradise have strikingly similar endings because both involve a faculty member or teacher asking a favor from a student during a late 1980's high school senior party, both have the student refusing to comply, and both have student killed by faculty member running him or her over with a automobile.
Glory Days and Forensics also end rather similarly, with a student being murdered by a teacher after confronting them with both their own wrongdoing and the fact that their glory days at school were in reality anything but.
Retroactive Recognition: A pre-fame Summer Glau and Mae Whitman among others have showed up as oneshot victims; Jennifer Lawrence appears as the present-day version of a teenage girl in another episode. Shailene Woodley makes an appearance as a sister of a Amish murder victim.
Rewatch Bonus: This happens frequently as new evidence puts previous flashbacks in a new light.
In the opening sequence of Forever Blue, this is said about the Cowboy Cop victim:
"Isn't is about time he got married?"
"You gotta go on a second date for that."
In that context, it makes him sound like a womanizer. However, once you realize that he's gay, you realize that he never went on a second date, not because he couldn't be satisfied by only one woman but because he couldn't be satisfied by any woman. To make matters worse, he was also secretly in love with his partner who he saw all the time. He probably thought that if he kept going out with women, he could suppress his feelings.
There's also the fact that his partner's wife is very cold to him. One thinks it's because he's late, then that it's because that they've been having an affair and she's angry about his sleeping around. Another flashback reveals it's because she walked in on him and her husband kissing.
Strawman Has a Point: When Moe Kitchener fills a complaint for harassment against Lilly for stalking him. When you think about it, she has no evidence but a Dying Dream to prove he was the one person that tried to kill her in "Into the Blue"
When Patrick Doherty points out that Stillman's repetitive actions to protect his team when they keep Jumping Off the Slippery Slope are more counterproductive than anything.
The Untwist: "8: 03 AM." The cases are reopened because it was discovered that the murders took place at exactly the same time on the same day, and Kat hoped that a connection could be discovered. Turns out there was none; it was a total coincidence, although the victims did know each other, something that wasn't apparent in the original investigation.
Also occurs in "Debut" and "Hubris", in which the killer turned out to be... exactly who everyone thought was the killer. The only reason the cases become as long and involved as they do is due to the villains' attempts to deflect suspicion off themselves.
Used interestingly in "Creatures of the Night." They know who did it from the beginning; the real challenge is proving it before the guy walks due to a ridiculous deal he took when he confessed to prior crimes.
What an Idiot: The revelation of who the doer was in "Time to Crime" was heartbreaking, to say the least, that doesn't really change the fact that he was a complete and utter moron. Dude buys a gun that he intends to use to kill someone from the same person he intends to kill, then instead of, say, shooting him right there, he waits until the guy is in the middle of a crowded park, then fires randomly into said crowded park, and not only misses his target, but hits his own sister by accident.