Dexter's Accomplices are those who have discovered Dexter's secret as a serial killer.
These accomplices are divided into three general categories:
- Masters have bent Dexter to their will at one point and had him kill for them.
- Apprentices are killers whom Dexter trained personally in his killing art.
- Partners (Partners-in-Crime) are aware of Dexter's killer nature and help him cover up his activities, even killing people to this effect.
Harry first came to know Dexter when his mother Laura Moser was working as a C.I. for him and later became his lover. After three-year-old Dexter witnessed his mother's murder, Harry rescued him from the cargo container, but abandoned Dexter's brother because he seemed too damaged. Later, when Harry realizes Dexter's tendencies, he taught Dexter to kill only murderers so that his urges will at least have a positive effect on the world.
- Murder by Proxy - Harry Morgan told Dexter to kill a nurse named Mary because she murdered several of her patients by overdose, and was attempting to do the same with him.
- Accessory to Three Murders - After that, Dexter killed an unnamed person, an unnamed drug dealer, and Juan Ryness, confessing all to his father. In Juan's case, Harry saw the dismembered body which caused him to vomit and take his own life three days later.
When Isaak's subordinate, Viktor Baskov, disappeared, Isaak came to Miami to find him, only to conclude that he was killed by Dexter Morgan. Isaak left a blood trail in his wake as he hunted Dexter down. Dexter admitted to Isaak that he did kill Viktor, claiming it was because he killed Mike Anderson. Isaak began to look into Dexter's nature as a killer. When Isaak's vendetta began to take a toll on the Koshka Brotherhood's profits in Miami, the bosses sent hitmen to kill Isaak. He was forced to form an alliance with Dexter, as he was the only one skilled enough to take out the hitmen (especially since he had the 'element of surprise' on his side).
- Murder by Proxy - Isaak coerced Dexter to kill a hitman named Oleg Mickic who was hunting Isaak, by having his henchman Jurg Yeliashkevych hold Hannah McKay (Dexter's girlfriend) hostage.
- Murder - After that, Dexter lured another hitman, Benjamin Caffrey, who was hunting Isaak to the Fearless ship where Isaak Sirko gunned him down.
Dr. Evelyn Vogel
From his childhood, Dr. Vogel knew that Dexter had urges to murder. She worked with Harry Morgan to create The Code of Harry. When she moved back to Miami, she requested his help to find and kill a serial killer who was leaving portions of human brains on her porch.
- Accessory to Four Murders - Through Harry, Vogel learned that Dexter killed Mary, an unnamed person, an unnamed drug dealer, and Juan Ryness.
- Accessory to Forty-Seven Murders - Vogel always knew that Dexter was the true Bay Harbor Butcher and did not report it to the police.
- Facilitation to Commit Murder - Vogel convinced Dexter to take care of a new serial killer in Miami who was a threat to her - The Brain Surgeon.
- Accomplice to Murder - Dexter killed A.J. Yates to rescue Vogel from her captor. After he was dead, she and Debra Morgan helped him clean up the scene and dispose of his body in the Gulf Stream.
Dexter and Miguel first met at Oscar Prado's murder scene and later developed a friendship. Both had an interest in finding Oscar's supposed killer, Freebo, but for different reasons. Dexter found Freebo first and killed him while Miguel was not far behind and caught Dexter with blood on his hands. Miguel slowly wormed his way into Dexter's world and eventually convinced Dexter to let him kill someone. Dexter taught him his own killing methods (except for dismemberment and disposal at sea). He also instructed Miguel to obtain absolute proof of guilt before he took out a potential victim.
- Accessory to Murder - Miguel witnessed Dexter exit Teegan Campbell's garage covered in blood after he killed Fred Bowman. Dexter managed to convince Miguel that it was done in self-defense.
- Accomplice to Murder - While playing golf, Miguel talked to Dexter about a case involving a wife-killer named Ethan Turner. Miguel later called Dexter to tell him the case against Ethan had fallen apart. Dexter then secretly killed Ethan on the Atlantic Sun. Miguel learned that Ethan went missing and confronted Dexter. He said it was a test of his resolve and he stood with Dexter in his vigilante acts.
- Accomplice to Murder - Dexter sought Miguel's help in killing an inmate held in a maximum-security prison named Clemson Galt. Miguel pulled it off by arranging Clemson to testify in a RICO trial and enabling him to escape. Dexter rendered him unconscious and they drive away with him. Dexter ended up killing him alone, leaving Miguel behind.
- Solicitation to Commit Murder - Miguel asked Dexter to kill Ellen Wolf claiming she was corrupt. (In reality, Miguel saw her as a political adversary and a career-threat to him.) Dexter nonetheless declined the request because she wasn't a murderer.
- Murder - Miguel informed Dexter about Billy Fleeter who was killing to pay off bookies. After learning Billy's routine and confirming that he's a killer, the two prepared a kill room and strapped him down to the table. Miguel then drove a knife into Billy's heart. Dexter took care of the disposal by himself.
- Murder - After he killed Billy, Miguel went to Ellen's house where he brutally killed her (by beating, strangling and stabbing her to death).
- Attempted Murder - After Miguel discovered that Maria LaGuerta was onto him for Ellen's murder, he went drinking with his brother Ramon Prado to establish an alibi. Unbeknown to him, Dexter was setting him up and captured him in Maria's house. He then took Miguel to Ellen's house where he garroted him. Dexter left his body in a park, having used the Skinner's M.O.
- Attempted Murder by Proxy - Even in death, Miguel almost had Dexter killed because he previously told George King that Dexter knew the location of Fred Bowman. This led to Dexter's capture by The Skinner. However, Dexter expertly escaped from the table on which he was to be killed, breaking his hand in the process. He then strangled King, but made it look like a suicide by throwing his body off a ledge. Dexter quickly escaped without being noticed. (King's murder was technically self-defense.)
Dexter and Lumen first came into contact when Dexter killed Boyd Fowler, a member of the Barrel Girl Gang, with Lumen as a witness to the crime. In time, she realized that Dexter saved her and told him that Boyd wasn't the only one who abused her. Dexter and Lumen later joined forces and killed the other members of the group.
- Accessory to Murder - Lumen witnessed Dexter Morgan kill a dead animal pickup officer named Boyd Fowler while watching from the attic door. Boyd was one of the men who raped Lumen and would have killed her, like with his previous victims, had it not been for Dexter's help..
- Accomplice to Murder - Lumen began to hunt the men who raped her. She forced one of them, Dan Mendell, to drive to Baywater Marina Warehouse where she shot him. Lumen then called Dexter to help clean up the blood. However, they found Dan still alive. When Lumen's instincts were proven correct, Dexter snapped his neck. Afterwards, Dexter set up the crime scene to frame Lance Robinson.
- Accessory to Murder - While outside the warehouse, Lumen saw Lance Robinson run away and Dexter chase after him. He then killed Lance and framed Dan Mendell.
- Assault - Lumen bashed Cole Harmon over the head after Dexter broke into his house for proof that he was one of the rapists.
- Accomplice to Murder - With two more names on their hit list, Lumen and Dexter pursued Cole as their next target. Together they set up a kill room in a hotel room in preparation of abducting Cole. Unexpectedly, Dexter was called onstage by Jordan Chase. Meanwhile, Cole noticed Lumen and chased her to the room where he attacked her. Dexter showed up in time to inject Cole with M99. He strapped Cole down and questioned him. Lumen then watched as Dexter collected a blood slide and stabbed Cole. Afterward, Dexter gave her the slide.
- Murder - While talking with Emily Birch, Lumen obtained the name of the unknown member of the Barrel Girl Gang -- Alex Tilden. After confirming his guilt, Dexter and Lumen captured him and took him to their kill room. Dexter then handed Lumen the knife and she stabbed him in the heart.
- Murder - After Jordan Chase kidnapped Dexter and Lumen, Dexter surprised Jordan by stabbing him in the foot and choking him out. He set Jordan up on his table, and let Lumen stab him in the heart.
Dexter and Zach first came into contact when Miami Metro Homicide was investigating his father for the murder of Norma Rivera. Dexter had a brief conversation with Zach and began to suspect him of being the killer. They started hanging out until Dexter found proof that Zach killed Norma and might kill another woman. Evelyn suggested that Dexter teach Zach code, but Dexter refused. While stalking Zach, Dexter realized that he wasn't targeting another woman, but his father. Dexter captured Zach and interrogated him in his kill room about why he was killing. After hearing his reasons, Dexter released Zach and took him under his wing.
- Murder - After receiving a brief lesson from Dexter on how to kill, Zach tracked down an old classmate named Shawn Decker. He prepared a kill room in the Windy Keys Motel, drawing on his experience from when he was Dexter's kill table. Things didn't go as planned, though, and he had to kill Shawn on the spot. Afterwards, Zach showed Dexter and Hannah the body of Shawn and they helped him cover up evidence of the murder.
She met Dexter at a "Narcotics Anonymous" meeting and was the one person there who could see through him. She became his sponsor and later his lover, as she did her utmost to divide him and his girlfriend Rita Bennett, initially succeeding. She even rode along with Dexter when the latter headed towards Naples to speak with Santos Jimenez, the murderer of his mother.
In time, however, Dexter realized Lila was going too far. She even broke into Rita's house, and gave Jimenez his location at Starlight Lanes. Dexter then split with her and made it clear that he did not want her anywhere near himself and Rita, or he would show her his bad-side or, as he called it, "The Monster."
She ignored Dexter's warning and started to mix with his workplace colleagues. She then framed Angel for rape in order to coerce Dexter into "taking her back." Later, Dexter told her that he was leaving Miami for good, so framing Angel was pointless. (At the time, he was planning to turn himself into the police.) Thus, Lila set out to learn where Dexter was going by stealing his GPS, while he, Rita, and the kids were on a boat ride. She followed the route and found James Doakes in the Cabin in the Everglades, who revealed to her that Dexter was The Bay Harbor Butcher.
- Accessory to Forty-Seven Murders - Sergeant James Doakes told Lila that Dexter Morgan was the real Bay Harbor Butcher.
- Murder - After Doakes told Lila that Dexter was the Bay Harbor Butcher, she lit a flame, locked the cabin door with the gas leaking. The cabin exploded and Doakes was incinerated by the blast. After Dexter learned that she murdered an innocent man (Doakes), Dexter targeted her as his next kill. However, because of Debra's interference, Lila had time to figure out his true motive. Lila then kidnapped his step-children, Astor and Cody Bennett (who believed her to be a genuinely nice lady) to use them as bait to lure Dexter to her loft. After Dexter arrived, Lila set her loft on fire and locked the three of them inside. Dexter, though, was able to save the children and escape. Later, Dexter tracked Lila to Paris where he stabbed her in the heart after he placed her in a garment bag.
Dexter thought he convinced Travis to turn away from Professor James Gellar (At the time, he believed Travis was simply a mislead, brainwashed person.)
- After Gellar allegedly murdered Lisa Marshall (Travis' sister), Travis vowed to help Dexter kill Gellar. Dexter, however, discovered that Travis was a schizophrenic who was having hallucinations of Gellar (whom Travis murdered three years earlier). Thus, Travis was the sole murderer all along, responsible for the Doomsday Tableaus. Thereafter, Dexter pursued the difficult goal of killing Travis, but he eventually ended up on Dexter's kill table in the Santa Maria de Laredo church.
Debra grew up with Dexter as his adoptive sister. Later, they both worked for the Miami Metro Police Department, she as an officer who worked her way up to Lieutenant, and Dexter as a blood spatter tech. They often worked together at crime scenes.
- Accomplice to Murder - Debra caught Dexter in the act of killing Travis Marshall. He convinced her to help him cover up the crime. She then bought gas from a nearby station and Dexter used it to burn up the church and the body of Travis, destroying all evidence (except a blood slide).
- Accessory to Forty-Seven Murders - Debra broke into Dexter's apartment and discovered blood slides and kill tools. After Dexter admitted to her that he was the Bay Harbor Butcher, he confessed to the murders of Mike Donovan, The Castillos, and Emmett Meridian.
- Accessory to Murder - Debra confronted Dexter and he confessed to killing Arthur Mitchell who had killed Rita Morgan because of him.
- Accessory to Murder - Dexter called Debra to meet him at the mausoleum where he confessed to her that the smoke coming from the chimney was Ray Speltzer.
- Accessory to Three Murders - Debra warned Dexter that Captain Maria LaGuerta was again investigating the Bay Harbor Butcher. To help Deb divert LaGuerta's attention, he confessed to killing Phillip Barnes, Christopher James, and Marvin Madden. Den later gave Dexter an incriminating photo of him with Phillip at a wedding.
- Accessory to Murder - Dexter called Debra to meet him in the parking lot and confessed to killing Viktor Baskov in order to warn her that Isaak Sirko was targeting both of them.
- Accessory to Six Murders - Debra called Dexter to meet at her house where he confessed to the murders of Boyd Fowler, Dan Mendell, Lance Robinson, Cole Harmon, Alex Tilden, and Jordan Chase, and to Lumen Pierce previously being his partner.
- Solicitation to Commit Murder - Debra asked Dexter to kill Hannah McKay to right the murder of Sal Price, an innocent man. Dexter, nonetheless, declined the request. At the time, Debra accepted his decision but, later, became angry when she learned the reason why -- Dexter was dating Hannah.
- Murder - Debra investigated a shipping container where she found Hector Estrada dead, Maria LaGuerta unconscious, and Dexter prepared to kill her. Deb pulled her gun, confused on what to do. Impulsively, she chose LaGuerta and shot her to protect Dexter.
- Accomplice to Murder - She witnessed Dexter kill Andrew Briggs. Afterward, she lied to the police about the circumstances surrounding his death.
- Accomplice to Murder - She witnessed Dexter kill A.J. Yates. Afterward, she and Evelyn Vogel accompanied Dexter when he dumped the body in the Gulf Stream.
While Dexter was working on the Wayne Randall case, he and Hannah began to bond. Because Hannah was a murderer, Dexter attempted to kill her but instead set her free. They immediately had sex on the kill table. Dexter revealed why he tried to kill her, and later told her about his Dark Passenger. Problems arose in their relationship when she killed Sal Price to protect Dexter and herself, and tried to kill Debra.
- Accessory to Murder - Dexter talked with Hannah about how killing Viktor Baskov was causing problems in his life.
- Murder - After Sal Price threatened Hannah with the prospect of ruining Dexter's life she confessed to killing Linda Johnson. She then poisoned Price, who died in Dexter's apartment.
- Murder - Hannah was kidnapped by Jurg, but outsmart him and killed him in self-defense, although she sustained a severe injury in the process. Debra rescued her soon afterwards.