Carl was a bit of a womanizer and a ladies' man. As one of the younger King brothers he always had to fight for his place in the family. He was also commitment phobic, and despite apparently finding his perfect match in Chas Dingle, his eyes wandered onto Eve Jenson and he wrecked what could have been a beautiful relationship.
Carl had a bad temper on him and was responsible for two accidental deaths - so he was not one to be crossed.
Carl first appears as the new driver for Tate Haulage. However, no one knows that he is a spy, reporting back to his family business, King & Sons, and going under the name of Carl McKenzie. Carl learns what Tate Haulage plan to bid for a new contract and, with this information, his family revise their bid and win the contract.Despite being married, Carl flirts with Louise Appleton and she agrees to a date until Carl's wife, Colleen, arrives and tells Louise that she is Carl's wife and mother of his children; Thomas and Anya before telling Carl not to come home. Louise slaps Carl and goes home so he moves into Holdgate Farm with his family but is "persuaded" to do some repairs to the roof, despite his fear of heights. Local postman Paul Marsden helps him and seeing his nerves about heights, starts teasing him and mucking about but stretches too far and falls, dying instantly. Not wanting people to know they were involved, Carl and his brothers, Jimmy and Matthew move his body to the back garden of the cottage Paul shared with his wife, Siobhan. She finds him and assumes he fell from their roof after fixing the television aerial.
2004-2005: Chloe Atkinson
Meanwhile, Carl bonds with Chas Dingle over feeling like they're bad parents for abandoning their children and tells her about Paul's death. They start dating but the relationship is rocky and during one break, Carl has a one-night stand with Chloe Atkinson. When she finds out Carl and Chas are back together, she decides to split them up permanently. She starts a campaign of poison pen letters and undermines Chas's trust in Carl, succeeding in her aim so he reconciles with Chloe but soon tires of her and tries to end it. Not wanting to let him go, she tells him she's pregnant, despite the fact that she isn't and starts trying to get pregnant before Carl discovers the truth. Chas discovers Chloe's lie and forces her to tell Carl the truth, that she isn't pregnant and never was. Before leaving the village, she reminds Carl that she could be pregnant as they weren't taking precautions. Horrified at his mistake, Carl tries to reconcile with Chas but she is not interested and leaves to join the army so Carl starts dating her cousin, Delilah. Realising that Carl wanted Chas, not her, Delilah encourages him to fight for Chas so he tracks her down and declares his feelings, accidentally dropping her after picking her up and breaking her leg. Consequently, Chas is discharged on medical grounds and reconciles with Carl and he proposes marriage but Chas refuses, until he does a wing walk to conquer his vertigo. They move into Home Farm with his father Tom and Chas becomes Jimmy's personal assistant.
2006-2007: Tom's murder
Tensions erupt when Matthew and Jimmy's ex-wife, Sadie King, declare their feelings for each other, move into Victoria Cottage and start a rival company. Matthew uses Carl to pass Jimmy false information so he loses an important deal while Tom and his fiancee, Rosemary Sinclair, insist that Chas is not good enough for Carl and on learning that Chas has been giving information about the Kings to Jamie Hope, whose sister died in the King's River Showhome disaster, Tom bullies/bribes Chas to end things with Carl. Chas, however, encouraged by her cousin, Eli, tells Carl the truth on Tom and Rosemary's wedding day. Later that day, Tom is murdered when he was hit over the head and pushed from his bedroom window, and his sons are the primary suspects.
The brothers are stunned to learn that they have a half-sister, Scarlett, daughter of their mother's nurse, Carrie Nicholls. Carl struggles to bond with her and he and Matthew try to buy her share of the business. Carl eventually softens but is uncomfortable around Carrie, as they had a brief relationship when he was a teenager but is grateful when Carrie helps evict Rosemary from Home Farm. Hari Prasad tells the police that he heard the King brothers discussing how they murdered Tom and Louise, his girlfriend, backs him up but the case collapses when Louise admits giving a false statement. After the acquittal, Carl admits to Jimmy and Matthew that he killed Tom. He reveals that he confronted Tom about Chas, hitting him when Tom called Chas names and then pushed him away, causing Tom to fall out of the window. Carl begins dating DCI Grace Barraclough in secret, unaware of her plan to learn who killed Tom, but Carl won't say. Grace ends their relationship and Carl gets drunk, telling Jimmy and Matthew about the relationship so Jimmy takes Carl abroad to clear his head. However, on his return, Carl deliberately gets arrested for drink driving so he can see Grace and tells her that he killed Tom and decides to confess. Jimmy watches as Carl and Grace go to the police station and as Carl stops to answer his phone, Grace carries on and is hit by a lorry. Grace dies and despite telling the police that he is a killer, the police ignore him as they are more concerned about Grace.
2007-2009: The De Souzas
Carrie's daughter, Lexi, visits her sister and becomes involved with Carl. He joins De Souza Enterprises, angering Matthew. Donald De Souza appoints Carl MD of his business, disappointing his daughter, Anna. Carl hires Lexi to be his PA, but discovers she has been passing information to Matthew, and ends things with her. Carl and Anna are attracted to each other and he is jealous of her relationship with Matthew and reconciles with Lexi, but when he tries to end their relationship, Lexi tells him that Carrie told her that he killed Tom. Donald buys Mill Cottage for Carl and he and Lexi move in together. However, on learning that Carl sent an important client to his brothers, Donald terminates Carl's contract and Carl returns to work with his brothers. Carl is saddened when he hears that Donald has died and Matthew admits causing his death by refusing to give him his heart medication. Knowing the guilt Matthew will live with, urges him to tell Anna but he refuses. When King & Sons is declared bankrupt and the bailiffs move in on Matthew and Anna's wedding day, Carl is furious to learn that De Souza Enterprises wrecked King & Sons's chances of survival and that Matthew will have an interest in the company as he is married to Anna, Carl blames Matthew for everything and reveals the truth about Donald's death at the wedding. This leads to a fight between him and Carl and Matthew drives a van at him. However, on seeing Anna standing with Carl, he swerves and is thrown through the windscreen, dying on the road.
Carl realises his only assets are Mill Cottage and a mortgage he gave Debbie Dingle and begins pressuring her for money. Carl, Jimmy, Lexi and Scarlett scrape together enough money to start a new haulage company. Carl tells Chas that he still loves her, but she insists they are history. Lexi proposes to Carl and he accepts, she sets a date but Carl goes missing on the day. He meets Chas and she insists she has moved on so he marries Lexi but is furious when he learns she has stopped taking precautions without consulting him. He reluctantly agrees to have a baby and Lexi gets pregnant but miscarries almost immediately as the pregnancy is ectopic. Tests done just after the miscarriage show that Lexi is unlikely to conceive again without IVF and Carl agrees to try IVF initially but soon changes his mind. Nicola insists that Carl tell Lexi, which he does, and they argue. She also argues with Nicola and Nicola goes into premature labour after falling down the stairs. Lexi apologises and Nicola forgives her. Later, after a nurse gives baby Angelica to Lexi while Nicola is in the shower, she takes her up on to the roof, simply wanting to show her the world. However, seeing Lexi sitting on the roof with baby Angelica makes Jimmy, Nicola and Carl panic that she is going to jump. Carl talks her down and she returns baby Angelica to Nicola and Jimmy after Carl admits that he doesn't love Lexi and wouldn't have married her if she hadn't known that he killed Tom. Lexi tells Carl that she is leaving him and joins Carrie in Canada.
2010-2012: Affair with Eve and downfall
Nicola insists Carl move out of Mill Cottage and he reconciles with Chas again after telling her partner, Paddy Kirk, about their affair. They are happy together for a while but, now getting bored, Carl begins an affair with Eve Jenson. Chas proposes to him and implies she is pregnant. Carl accepts and gives her money for the wedding and ends things with Eve but on the day, Chas reveals Carl's affair with Eve to the village and humiliates him. Carl becomes bitter towards Chas for stealing his money and is accused of starting a fire near her house, which engulfs the village and kills Terry Woods and Viv Hope. Carl is arrested but later freed. He and Chas have a one-night stand months later and he comforts her when her son, Aaron, is charged with murder. Carl borrows money from Scarlett to hire a lawyer for Aaron but when Aaron refuses to take it, invests it in his business instead. Disgusted, Scarlett discovers what he has done and leaves the village.
Carl is caught speeding on CCTV and he convinces Rodney Blackstock to take his speeding points for him, in exchange for a job. The police reveal that a cyclist was hit during the incident and Carl is shocked when he learns Rodney could go to prison. Rodney blackmails him into giving him money and a job. Jimmy discovers what is happening and confronts Carl.
Carl discovers Chas has been having an affair with Cameron Murray and begins blackmailing them for the£30,000 that Chas took from him. Carl slowly becomes obsessed with getting Chas back and starts pushing everyone away, including Jimmy. Carl asks Chas to run away with him and she agrees, wanting to keep him sweet. However, on her wedding day, Carl has a fight with Jimmy. However, after she marries Dan Spencer, she escapes him at the wedding reception. She bursts into The Woolpack and start getting her clothes packed. She pours herself and Diane Sugden a drink before Dan sees her with her bags packed. She plans to leave Emmerdale in Dan's camper van but Carl stands infront of the van to stop her from leaving. Carl sees that there is a bed in the back of the camper van and invites Chas into bed with him. They kiss in the bed but Carl has an idea for Chas to throw her wedding ring away and Chas follows Carl's idea. Carl starts kissing Chas on the neck and starts pulling her dress sleeves down, Chas sits up thinking that Carl is going to rape her. They both get out the camper van and Carl pins her against the wall. Chas tries to escape from Carl and slaps him in the face. Carl grabs her by the hair and pulls Chas to the ground, saying that isn't anyone's if she isn't him and finally admits that he killed Tom all because he badmouthed Chas the night he killed. Chas manages to grab a brick and hits Carl over the head with it.
Chas runs away from Carl and gets spotted by Cameron, so Cameron went to go see what she was running from. She runs back into The Woolpack where Diane informs vicar Ashley Thomas that Debbie Dingle has given birth to her son Jack. Carl struggles to get up, so Cameron grabs him up and pulls him onto the floor. He threatens Carl to leave Chas alone and doesn't tell Cain or Debbie about what is going to do to him Carl falls back to the wall while Cameron holds the brick. Carl grabs Cameron and tells him that bad things happen to people around him and he can just walk away untouched and not get into trouble for it. He says that he is going to do it again to Cameron because he thought that he was indestructible before Cameron promptly hits Carl over the head with the brick, killing him. Cameron bends over to see if he can find Carl's pulse but can't feel it. Cameron steals Carl's phone and fleas. Adam Barton and his girlfriend Victoria find him there a couple of minutes after he was killed.
- In September 2012, it was announced that a character was going to die in the 40th anniversary live episode. The identity of the character who was to die was kept secret until the episode was broadcast a month later, where the character was revealed to be Carl.
- Tom Lister had posted tweets prior to his character's departure to Nick Miles that he was considering leaving the show for other work.
"Mr Windsor? Carl McKenzie. Sorry to bother you. One of your lads said you might be looking for drivers." (First line, to Scott Windsor)
"I stuck up for you! You know, my dad thought you were trash! Oh, I already know what he thinks of me now. Ever since he badmouthed you, and then I stuck up for you, and then he said something else, and then I pushed him! And then he fell! From that window, Chas! I killed my dad for you!" (To Chas as he confesses to her that he killed his father)
"You should be grateful, you stupid bitch!" (To Chas before she hits him over the head with a rock)
"I am. Shall I tell you why? A few years ago, I sat down with our Jimmy after Matthew died and I told him I thought I was cursed. But I'm not. I'm charmed. Bad things happen to people around me and I walk away untouched and get away with it! I've done it before. And I'm gonna do it again to you, this time, and there is nothing you can do to stop me! And I'll tell you why that is, as well, shall I?! Because I'm indestructible!" (Final line before being murdered by Cameron Murray)