"I killed Muriel because I wanted to and because I knew I could get away with it. I wanted to see what it was like to look into a healthy person's eyes, someone untouched by illness or old age, at the instant they realized they were going to die and were powerless to stop it. It's unbelievably exciting. Better than sex. Better than anything."
—Dan Marlowe, The Past Tense
Dr. Mark Sloan and his cop son Steve have fought literally hundreds of killers and other criminals through the years, but some go a step further.
All spoilers are unmarked. You Have Been Warned!
TV Series
- "Guardian Angel": George Ridgeway, the mayor of L.A. who dreams of running for governor, harbors a dark secret behind his hard-working image. Having raped his step-daughter Melissa in private for years, leading to her becoming horribly traumatized and unhealthy, Ridgeway's actions lead to his wife Lauren murdering him upon discovering his behavior.
- "Living on the Streets Can Be Murder": Cheryl Dante, real name Cheryl Ormand, is a disgraced medical practitioner who has decided to turn her talents to a more depraved pursuit. Masquerading as the kind head of a charitable organization for the homeless, Cheryl uses her institute to cover up the fact that she is killing the homeless and harvesting their organs to sell to wealthy clients. Cheryl has done this to many people across the country, her latest spree involving at least 5 victims left dead in the streets. When her partner-in-crime Tom Winston tries to back out of the ordeal, Cheryl tries to murder him before attempting to vivisect Dr. Sloan for investigating her.
- "X Marks the Murder" Part 1: Michael Dern, aka the Casanova Killer, is a misogynistic Serial Killer who, due to his own self-pitying, has made it his mission in life to hunt down and kill women. Using his job as a gas station attendant, Michael charms women into letting him near them before murdering them. Gaining an obsession with police consultant Dr. Mark Sloan, Michael targets Sloan's friend Dr. Amanda Bentley and gleefully reveals how he plans to kill her. Michael ultimately reveals he aims to increase his victim count by two or three a day just to bask in the attention, and is happy to mock Sloan with how much his victims suffered, just to mess with him.
- "Delusions of Murder": Dr. Gavin Reed is a repulsive therapist who has a dark secret: he sexually abuses his patients while they are under hypnosis. Gavin psychologically torments his patients while he sexually abuses them, and his actions nearly lead to one dying from a hemorrhaging due to a miscarriage. Reed has been slowly driving his patient Barbara Bennings insane with both his sexual abuse and drugs. After Reed's wife threatens to expose his habits if he doesn't hand over his company, Reed stabs his wife In the Back. Hypnotising and framing Barbara, Reed is fully prepared to make her take the fall for his crimes and later tries to murder her himself after she confronts him.
- "An Education in Murder": Noelle Andrew is a seemingly lovely and sweet young woman with a history of transferring schools. In truth, Noelle is a devious, sadistic sociopath who ropes in her peers with a series of "favors" to enslave them to her before murdering them when she's through and sometimes blackmailing them into sexual favors. Noelle leaves a string of bodies in her wake, using her proxies to commit murder for her while psychologically destroying them.
- "Blood Will Out": Martin Rutgers is a heartless slimeball of an NSA officer who sees it fit to arbitrarily lock down Community General Hospital after a madman takes a nurse hostage. The "madman" is in fact Rutgers's pet virologist Dr. Gregory Othon, whom Rutgers tricked into creating a Synthetic Plague for his own mercenary purposes. The design and purpose of this plague is terrifyingly simple: it's been specifically tailored to kill the population of entire cities overseas, allowing Rutgers to take over the resultant "real estate" without a sniffle of contention from his ostensible higher-ups. Utterly without regard for life, Rutgers kicks off the episode by having an entire restaurant shot up and massacred just to pick off Othon, and spends the rest of the episode trying to kill the doctor when he survives, as well as any of Community General's innocent staff who get in his way in the process. Rutgers even pettily rubs his federal protection in Steve Sloan's face, noting even after Othon dies and all evidence of his misdeeds apparently cleared that he'll strip Steve of his badge "just for fun!"
- "Murder x 4": Ernest Rogin is the head of the Montana Mutual insurance company, which acts as a front for his assassination business. Rogin forces terminally ill patients into being his pet assassins, or else their insurance won't be paid to their families, and is perfectly happy ruining the lives of desperate people who just want to provide for their families. Rogin's assassins end up cutting a path of destruction across the city, from a drive-by shooting that kills a woman to a bludgeoned real estate agent, and the shooting of a travel sales agent that leads to an entire room taken hostage and threatened. When Rogin is confronted by Dr. Mark Sloan and his son Steve to try and stop his latest killer from taking out their victim, Rogin shrugs and holds it over their heads in an attempt to weasel out of consequences, stating that her death "won't be on my conscience. I don't have one."
- "Voices Carry": Howard Weber is the head of an oil company who's secretly "The Clown Killer". Killing young women all across the world and leaving clown face paint on them as his Calling Card, with Howard himself guessing his body count to be close to 40 victims, Howard returns to L.A. to continue his killing spree. Mocking the officer chasing him, Harry, with his return, Howard frames one of his employees, Randy Horsting, for the murders, and upon being caught by Sloan, hopes to gain fame from his crimes. Howard Weber is revealed to have a wife and daughter of his own, but laughs when Mark Sloan inquires about them; he admits he'd cheerfully kill his own wife like all the other women he's slain if there were a way to get away with it.
- "Murder, My Suite": Ariel is a thief who hopes to steal from a hotel vault. Manipulating several men into doing her bidding by making them give up everything to be with her, Ariel tricks a med school grad student named Alex into bringing her a deadly virus, using it to infect the hotel as a distraction. With over two dozen people at risk of dying from the virus's effects, Ariel kills Alex and then her other partner to tie up loose ends, willing to kill her entire crew to keep the money for herself.
Novels, by Lee Goldberg
- The Silent Partner: Freddy Meeks, the titular "Silent Partner", specializes in copying the killings of other killers. A true crime author and police consultant, Meeks becomes so fascinated by murder that he begins to murder others. Meeks uses his position to learn the modus operandi of various wanted serial killers, and then copies their murders so that the killing is assumed to be one of their sprees. Operating for years, Meeks' operation is only discovered by Dr. Mark Sloan finding discrepancies in his cases, and as a result, Meeks tries to off him. Framing his old friend Lou as the killer, Meeks makes his death look like a suicide in a way to escape punishment. Ultimately, when confronted, Meeks admits that he kills for the sheer thrill of it.
- The Past Tense: Dan Marlowe, seemingly just a harmless old widower with terminal cancer, turns out to be the first—and possibly the most sadistic—killer Mark ever fought. A lifelong psychopath motivated by nothing but his need for stimulation, Dan enjoys paralyzing his victims to leave them aware but helpless against everything he does to them. Mostly targeting women, over years Dan leaves one in a running car that goes off a cliff; throws another down the stairs; buries another alive; cuts one victim's throat when she's already suffocating, just to increase her agony; and finally outright tortures his final victim to death, keeping her alive for fifteen minutes before she expires. Approaching the end of his life due to his cancer, Dan hopes to make Mark his masterpiece, planning to torture him for hours before taking out his heart and showing it to him while he's alive. Even after he's gunned down, the novel ends with the haunting implication Dan not only killed his own wife, but Mark's as well.
- The Dead Letter: Jimmy Cale, initially seeming to be the novel's Asshole Victim, secretly faked his own murder and framed his own so-called best friend Bob Yankton for it, resulting in Yankton facing capital charges. Cale reinvents himself as "Robin Mannering", mostly to escape charges of embezzlement, but also to leave a life he hates, including a wife who divorced him for his womanizing and a teenage daughter he hates just for existing. Cale systematically murders anyone who knows his identity, resulting in almost half-a-dozen murders even before the book has started, and hires a hitman to kill a private detective on his case, resulting in the detective going off a cliff. When Cale thinks he's dying of a rare form of lymphoma and needs a compatible blood donor to survive, Cale opts to use his daughter—and subsequently orders the hitman to rape, torture and murder her afterward so he's rid of her, threatening the same fate for her mother first. Cale even plans to kill everyone involved with the operation he thinks is going to save his life to once again cover up his identity, not even planning on sparing his hitman.
