Beware of spoilers, only spoilers from the seventh and eighth seasons are meant to be blacked out. All character sheets contain major spoilers. Proceed reading at your own risk.note
A young man who was an intended victim of Dexter.
- Alas, Poor Villain: Even Dexter feels sorry for him when he kills himself.
- Dark and Troubled Past: Jeremy was raped by the person he killed.
- Driven to Suicide: He slices his wrists open while in holding.
- Rape as Backstory: Jeremy was raped, and killed the boy who did it. Out of shame, he never told anyone which led Dexter to hunt him down.
- Tragic Villain: Jeremy just wants to feel human. Too bad he does it by killing people
An initial suspect and later almost-victim of the Ice Truck Killer.
- Alliterative Name: Tony Tucci.
- An Arm and a Leg: Rudy cuts off his hand and foot to leave as messages for Miami Metro.
- Big Fun: He's a larger man with a ridiculously upbeat attitude.
- Chuck Cunningham Syndrome: Disappears from the series without even a ripple, to the point where you could wonder whether the Ice Truck Killer finally finished him off after all and no one noticed.
- Nice Guy: Despite being held for days and mutilated, he's friendly, upbeat, extremely affable and even apologizes to Deb and Doakes for not being able to remember more. Even then, he goes the extra length to recall a very traumatic memory just to help them.
- Red Herring: He's initially suspected of being the Ice Truck Killer, only for it to be revealed that he was another victim.
A criminal informant who develops a romantic interest in Debra.
- Butt-Monkey: Nothing ever goes right for him. He's manipulated by Quinn, tortured by a maniac, neglected by his girlfriend who then cheats on him and dumps him. All he ever got from working the crew was a flayed back and a broken heart.
- The Informant: He's a genuinely Nice Guy who just got in some trouble, so he's helping.
- Nice Guy: When hearing about Deb's infidelity, his first reaction is talking about how to mend the relationship, rather than walking away.
- Put on a Bus: As with most relationships on the show, shortly after the next season they quickly broke up and he was never heard from again
A defense attorney and Miguel Prado's main rival.
- Amoral Attorney: Subverted. She's not as straight-up charming as Miguel, but she has the integrity and morals that Miguel makes such a show of pretending to have. Then again, she's gotten off a number of scumbags who went off and killed again, so she has blood on her hands.
- Asshole Victim: Whether she was principled or greedy is beside the point. She was thoroughly rude and unpleasant, and most viewers were not sad to see her go.
- Good Is Not Nice: She works by the book, and claims to truly believe that she thinks her clients are innocents who deserve a fair trial. Though it's ambiguous as to whether she means it or if she does this for the money.
- Jerkass: She's incredibly by the book and she's not known for being a nice or liked lawyer because of it.
- Jerk with a Heart of Gold: That said, she's a good person at heart and wants her clients to have fair trials.
- Mrs. Robinson: She flirts heavily with a young bartender.
- Sacrificial Lion: Miguel killing a principled character underscores that he means business.
- Smug Snake: Incredibly arrogant and unpleasant. It's no wonder Miguel wanted her dead, "innocent" or not.
Miguel Prado's real estate agent wife. Usually called "Syl".
- Crusading Widower: Sylvia is devastated when she hears of Miguel's death. However she helps prepare Rita for her wedding and is last seen enjoying the wedding.
- In-Series Nickname: Rarely called "Sylvia", instead going by "Syl".
- Nice Girl: Syl is a sweet, friendly person.
- Put on a Bus: Although she befriends Rita and Dexter in season 3, yet she's not seen again afterward. The Bus Came Back for the penultimate episode in the series when she helps Dexter sell his place.
The controlled and meek wife of Arthur Mitchell.
- Abusive Parents: Sally becomes psychologically abusive after Arthur's death.
- Bus Crash: Jonah kills her in retaliation to the verbal abuse killing his sister.
- Dropped a Bridge on Her: She's killed off-screen by Jonah during season 6.
- Extreme Doormat: She is totally cowed by Arthur's abuse and won't ever contradict him, even as he abuses both their kids.
- Put on a Bus: She vanishes after Season 4.
- Stepford Smiler: She plasters a big smile on her face to disguise the awful truth of her marriage.
- Stockholm Syndrome: She's come to rely on Arthur, making excuses for him and obeying him unquestioningly.
The abused teenage son of Arthur Mitchell.
- Big Brother Instinct: He was extremely protective of Rebecca.
- The Bus Came Back: In Season 6, he is visited by Dexter after he learns of Rebecca and Sally's deaths.
- Butt-Monkey: He is horribly abused by his father (both physically and emotionally) for years. After his father's death, he ends up dealing with an emotionally abusive mother and a little sister Driven to Suicide.
- Calling the Old Man Out: At Thanksgiving, he goes on a rant against Arthur.
- Knight Templar Big Brother: After his sister's suicide, his rage towards his controlling, imposing mother resulted in his mother's death.
- Matricide: He killed his mother after her attitude and behaviour led to Rebecca's suicide.
- Near-Death Experience: Was almost killed by Dexter, but in the end he lets him go.
- Not So Different: After killing his mother, he feels guilty and claims to be not so different from his father.
- Put on a Bus: At the end of Season 4, he vanishes with the rest of Arthur's family.
- Secret Keeper: Along with Lumen and Hannah, he's the only character who knows of Dexter's secret and is still alive.
- Stepford Smiler: Like the rest of Arthur's family, he played the role of a happy family. He's the first to give up on it and rip his dad a new one. It would have likely ended in his death if Dexter wasn't there.
- Two First Names: Either "Jonah" or "Mitchell" can be used as a first name.
The young daughter of Arthur Mitchell.
- Broken Bird: She's so broken that she even tries to seduce Dexter and be his Sex Slave just so she can get away from her father.
- Bus Crash: Commits suicide due to her mother's verbal abuse before her brother's reappearance in Season 6.
- Driven to Suicide: She killed herself in a bathtub after her mother's verbal abuse ended up being too much.
- Dropped a Bridge on Her: A fairly prominent supporting character in season 4, she dies off-screen in season 6, appearing only as a photograph.
- Fille Fatale: She clumsily tries to seduce Dexter, just so she can escape her father.
- Put on a Bus: Vanishes with the rest of the Mitchell family at the end of Season 4.
- Shrinking Violet: Jonah describes her as being this, which led to her suicide.
- Stepford Smiler: Like the rest of the Mitchell family, she puts on a cheerful facade to hide the abuse.
The Morgan-Bennett family's overly-friendly neighbour.
An Irish nanny hired by Dexter.
- Chuck Cunningham Syndrome: Vanished after Season 5 was over. It was not explained why Harrison's nanny was changed.
- Friend to All Children: Her instant bonding with baby Harrison implies she is great with kids.
- Magical Nanny: She was a fantastic nanny to Harrison and very understanding of Dexter's schedule within reason.
- Nice Girl: She has a very gentle personality.
- Sheep in Sheep's Clothing: In her debut episode, she appears to be too perfect to the point of being ambiguous, leading Dexter and the audience to think she's hiding something dark. It turns out she was really a normal woman who happens to be a very good nanny.
A woman whom Dexter inadvertently rescues from the house of one of his victims in season 5 after she sees him in the act. At first frightened and mistrustful of Dexter and traumatized by her brutal kidnapping and torture, Lumen later convinces Dexter to aid her in tracking down and killing what remains of the group of men who brutalized her.
- And This Is for...:
- A non-verbal variant when Alex Tilden is on the "kill table". She looks around the room at the pictures of his other victims, closes her eyes and moves in for the kill. Her actress confirmed this was "This is for all of you" moment.
- When she fatally stabs Jordan Chase, she exclaims "This is for everyone you've ever hurt, even Emily."
- Birds of a Feather: With Dexter. "It is a law of nature that elements will want to unify. Single cells thrash about in a petri dish until they coalesce."
- Broken Bird: She's traumatised after undergoing a horrific gang-rape and torture.
- But Now I Must Go: Her departure. She says she's done with her revenge and cannot continue living with Dexter when her darkness is gone.
- Combat Pragmatist: When you're a slight women with no combat training, you have to be pragmatic.
- Gut Feeling: She's accurate about Dan Mendell the dentist. He just smelled like her rapist.
- Hair of Gold, Heart of Gold: Before she was turn into an angel of revenge, she was just an angel.
- Knife Nut: "Lookit those!" Dexter buys her one, and it's like a boyfriend buying his g-friend jewellery or a box of chocolate.
- Meaningful Name: Lumen is connected with light. The word lumen is also associated with anatomy, in particular the space within the arteries and veins through which blood flows; it becomes especially meaningful with her last name.
- Nervous Wreck: Her initial reaction after she's freed by Dexter. Then, she decides to take revenge.
- Outlaw Couple: Lampshaded by Masuka in 5x11, who compares her and Dexter to Bonnie and Clyde. This does not sit well with Dexter.
- Put on a Bus: After her 'darkness' leaves, Lumen decides to go back to the life she used to have.
- Relationship Upgrade: From stranger to lover for Dexter.
- Runaway Bride: Why she moved to Miami; unwanted wedding.
- Scars Are Forever: Her back has several horrible scars from her torture. They don't look like they'll ever heal.
- Sympathetic Murderer: With the help of Dexter, she hunts down and kills a group of men who brutally raped and tortured her.
- Took a Level in Badass: She goes from a broken victim to being able to take revenge and kill the people who victimized her with Dexter's help.
The sister of Travis Marshall.
- Big Sister Instinct: Lisa is very caring toward her younger brother, Travis. The fact that he is always working is very upsetting to her, and she wishes that he would spend more time with her.
Once on Death Row, Samuel Wright is now a reformed man of God... or so he says. Miami Metro are still highly suspicious of him, and don't know if he's honestly changed or has different intentions.
- The Atoner: He helps criminals and gang members reform themselves to atone for his own violent past.
- Badass Pacifist: He stands still and simply tells the above attackers that he's not afraid to die.
- Badass Preacher: He's gone from a criminal to a man of God, but still retains all his toughness.
- Bloodstained Glass Windows: Had his life-changing epiphany while beating the crap out of a guy in the chapel of a prison.
- Good Is Not Soft: Certainly not all of the time. He once killed a man and outlets his violent tendencies on a punching bag.
- Good Shepherd: This man of God has set up a garage where he employs ex-cons, and tries to help them better themselves.
- HeelFaith Turn: He had a conversion experience that led him to becoming a man of God, surprising even Dexter who had plans for him.
- The Mentor: He tries to help Dexter put aside his Dark Passenger and bring out his good instead.
- Messianic Archetype: Mos Definitely. He cares for the weak, tries to inspire them to be good people, sees the good in everyone, and his last act is to forgive his killer. In a twist on the usual trope, he was not always this way.
- My God, What Have I Done?: See Bloodstained Glass Windows. When he saw the sun shine in through the stained glass windows, he began to regret his life of crime.
- Not Afraid to Die: He knows what's waiting for him so why should he be afraid?
- Not So Different: Dexter recognizes that Brother Sam had a Dark Passenger. It's Sam's ability to find the light within his own Darkness that intrigues him.
- Obi-Wan Moment: On his deathbed, he asks Dexter to forgive his murderer.
- Odd Friendship: To the rest of Dexter's social circle, his friendship with a former legendary gangbanger known for his body count would seem .. Odd. Unknown to them the two have a lot more in common than they know.
- Reformed, but Rejected: The police don't trust him in the slightest, but his small community respect him and rely on him heavily.
- Reformed Criminal: He found God while in prison.
- Turn the Other Cheek: Tries to get Dexter to do this in regards to Nick who had betrayed Brother Sam and fatally shot him. Dexter tried to respect his friends wishes, then Nick had to start laughing about getting away with it.
A professor who was having an affair with James Geller.
A prisoner who embarked on a several-day killing spree with his teenage girlfriend, Hannah McKay.
- Beard of Evil: A Van Dyke beard.
- Driven to Suicide: Decides to end his prison sentence by running in front of a speeding truck.
- Friendly Enemy: He's pretty decent to Dexter.
- Jerkass: He's unsurprisingly ill-tempered when dealing with his jailors.
- Manipulative Bastard: He manages to sneak his way into the sun for a few days, before opting out of his sentence via roadkill.
- Outlaw Couple: With Hannah he went on a killing spree.
- Two First Names: Either "Wayne" or "Randall" can be used as a first name.
A True Crime fiction writer doing a follow-up to his earlier book about the killings by Wayne Randall.
- Going for the Big Scoop: Played with, he is smart enough to avoid the usual methods of Hannah McKay, but he bites the dust anyway.
- Good Is Not Nice: He isn't above engaging in bribery in order to expose those who have fallen through the cracks of the Miami justice system.
- It's All About Me: His goals only extended to furthering his own success as a novel writer.
- Intrepid Reporter: He's very determined to push out another book based around Wayne and Hannah, even putting himself in danger.
- Oral Fixation: Has a fondness for biting things. This is used to poison him.
- We Hardly Knew Ye: He dies fairly quickly after his introduction, poisoned by Hannah.
A woman who went on a killing spree with her boyfriend as a young girl, before gaining immunity after it was discovered he kept her in line with fear. This was later revealed to be a lie, with Dexter and Debra finding out she took an active role and tends to poison her problems away.
- Abusive Parents: Her father almost drowned her as a child to make her 'sink or swim'. He's gotten no better, fully ready to send her to prison just to gain a slight benefit for himself.
- All Girls Want Bad Boys: She has a thing for dangerous men. First Wayne Randall, and then Dexter.
- Bitch in Sheep's Clothing: To the point that it's hard to tell how many of her sweet scenes are genuine or just manipulation.
- Consummate Liar: She lies easily to the likes of Sal Price, even squeezing out some tears for his benefit.
- Dating Catwoman: Hooks up with Dexter, much to Debra's chagrin.
- Easily Forgiven: In Season 8 Dexter forgives her for trying to kill Debra extremely quickly once she shows up again, and Hannah in turn forgives him for turning her in to the police. This allows them to resume their relationship. Even Debra ends up forgiving her shortly afterwards.
- Freudian Excuse: Her father was a cold-hearted and self-serving individual who threw Hannah into ocean water, which nearly resulted in her drowning.
- I Did What I Had to Do: Her reason for killing a man who molested her.
- It's All About Me: Isn't afraid to kill anyone who gets in her way, though she claims that she doesn't enjoy killing and she only does it when she thinks it's necessary (addressed below).
- Karma Houdini: Played with. She dodged being punished for her actions, but as soon as she did she learned Dexter was dead. Of course, it turns out in the next scene he's just faking it, but she will probably never know.
- Master Poisoner: She has killed at least 3 people with poison without leaving any traceable evidence.
- Morality Pet: To the point that Dexter's love for her helps him let go of his homicidal urges in the last season.
- Not So Different: Bonds with Dexter on account of their mutual killing agendas.
- Outlaw Couple: With Wayne Randall, and later with Dexter; relationships with other killers.
- Parental Substitute: She's seen this way by Dexter's son Harrison who adores her.
- Serial Killer: With Wayne Randall, and later kills several people.
The son of Ed Hamilton, a rich "friend" of the Miami Metro Police Department. A young budding Serial Killer, he killed a woman named Norma Rivera in an attempt to stop his father's affairs, which were ultimately hurting his own mother. Troubled by the continuing urges, Dexter Morgan takes Zach under his wing and begins teaching him the Code of Harry in hopes that he can provide the necessary lessons that can make Zach like he is, and prevent him from being caught.
- Abusive Parents: A unique example in the form of his father, Ed Hamilton. While Ed spoils his son rotten with the best luxuries money can buy, he is also emotionally distant and implied to be abusive towards Zach's mother.
- The Apprentice: Dexter teaches him the Code of Harry so he can be a "neat monster" too.
- Anti-Hero: A nominal example given that he begins follows Dexter's lead by murdering serial killers in order to contain his sadistic urges. However, the Brain Surgeon kills him before he can fully internalize the Code of Harry.
- Bitch in Sheep's Clothing: His image as a handsome, charming young man serves as a convenient disguise for his true nature as a bloodthirsty Serial Killer in the making. Partially subverted in later episodes when he is revealed to be little more than a less disciplined version of Dexter Morgan given that he genuinely loves his mother and looks up to Dexter much the same way that Dexter himself once looked up to Harry.
- Creepy Souvenir: He takes photographs of his victims.
- Cruel and Unusual Death: The Brain Surgeon uses a bonesaw to cut into his cranium while he is still alive.
- Idle Rich: The fact that his father is filthy rich gives him a lot of free time to pursue his... "hobbies".
- Lonely Rich Kid: Ultimately revealed to be this in "This Little Piggy". This is one of the primary reasons that Dexter decides to take him on as an apprentice instead of killing him.
- Not So Different: From Dexter. He also has murderous impulses.
- A Pupil of Mine Until He Turned to Evil: Dexter fears this is the case but it's subverted when it turns out he's not the one who killed Cassie.
- Sacrificial Lion: Is suddenly killed by the Brain Surgeon in "Are We There Yet?"
- Screw the Rules, I Have Connections!: His family's wealth is the primary reason he has been able to evade arrest or suspicion for his behavior prior to meeting Dexter.
- Stuffed into the Fridge: His partially brainless corpse is left sitting in Dexter's house.
- Two First Names: Either "Zach" or "Hamilton" can be used as a first name.
A former Miami Metro detective who now owns his own private investigation company. Deb ends up working for him after quitting Miami Metro.
- Fake Guest Star: Appears in every episode of the final season, and accomplishes quite a bit more than expected. He even manages to get his own story arc toward the end of the season.
- Jerkass: By the end of the season, he's blows off Debra and basically smug about catching Hannah McKay.
- Reasonable Authority Figure: Tolerates Deb's unprofessionalism partly out of concern for her and because she does get results.
- Sharp-Dressed Man: He favors awesome suits, even when doing footwork for the job.
- Waking Up Elsewhere: In the series finale and fate in the show, after Hannah drugged him.
- "Well Done, Son!" Guy: He had a very tense relationship with his father; he was expected to go into the family business, and he rebelled by going into law enforcement.
A former finance executive who moves in next to Dexter Morgan looking for a quieter life.
- All Girls Want Bad Boys: She was greatly fascinated in Dexter, finding the "unavailable, mysterious guys" the most appealing to her.
- Girl Next Door: Literally, as in she moves in next door to Dexter. However it's subverted in the sense that "average normal wholesome girl" is not compatible with Dexter.
- Sacrificial Lamb: A sweet girl who quickly falls victim of the Brain Surgeon.
- We Hardly Knew Ye: Exits the story after just a few episodes.