During his time living in Coronation Street, Karl had an affair with Sunita Alahan, which led to his separation from Stella. After being thrown out of Sunita's 7 Coronation Streethouse due to his laziness, Karl took a darker route in his desperation to win Stella back, including kidnapping her and later burning her partner Jason Grimshaw's van. After setting the Rovers on fire, he indirectly killed Toni Griffiths and later killed Sunita in hospital (she had confronted him in the pub and been trapped in the blaze).
Over the next few months, Karl began to settle down again with Stella, while trying to hide his guilt over the Rovers' fire and Sunita's death, but was eventually found out. On his wedding day, Jason and Dev Alahan pieced together Karl's involvement in the fire. Karl later surrendered to the police after injuring Dev and briefly holding Stella hostage in the Rovers.
Karl was a taxi driver who grew up in Manchester. He first met Stella in 2006 when she needed a lift when stuck in the rain, and he gave her a lift home. Shortly afterwards, they began a relationship and Karl cheated on her several times.
2011-2012: Arrival in Coronation Street
In June 2011, Karl arrived in Coronation Street along with Stella and her daughter Eva Price; Stella had became the new Landlady of the Rovers Return. They moved in with the pub's owner Steve McDonald.
Karl got a job at Street Cars in June 2011. Later in the year, he won £1,000 from Ciaran McCarthy playing poker with some of the lads in the back room of the Rovers. This was Ciaran's and Michelle Connor's wedding money, but Karl gambled it away.
Karl developed a gambling addiction and spent his Street Cars fares at the The Sunset Casino. Despite winning a lot of money he lost it all in one gamble. When Lloyd Mullaney questioned him about being absent all day, he made up a story that his car had broken down. Unknown to Karl, Lloyd had tried to kiss Stella after helping her in the Rovers, as she was supporting him after his break-up with Cheryl Gray.
2012-2013: Affair with Sunita
In 2012, he started an affair with Sunita Alahan and began creeping about. He almost got caught out by Dev and Kevin Webster. In July, Karl resumed his affair with Sunita for one night until Stella and her daughters Leanne and Eva came back to the Rovers to find Karl and Sunita. Following her heartbreaking discovery, Stella broke up with Karl; she banged on Sunita's door, causing several of the neighbours to emerge. Stella then slapped Sunita before calling her a slag just as Dev came outside. Later that night, Karl had to sleep in his cab after Stella threw him and his belongings out. He was sacked by Lloyd the following morning.
Karl moved in with Sunita at 7 Coronation Street after Dev allowed her to continue living there. Karl still missed Stella and began to regret his actions and disliked being with Sunita. Karl pleaded with Stella to take him back, however she kept refused every time. When Gloria turned up on the scene, Karl began asking her to talk to Stella to no avail. When Karl came to realise that Sunita had deleted his text message to Stella on the night she wanted to rekindle their romance, he angrily confronted Sunita. He returned to find her changing the locks of the house. Karl moved into a bedsit and begged Steve to give him his job back, which Steve agreed to do after talking with Stella.
In 2013, Karl began to spiral out of control. When Gloria's new fiancé Eric Babbage died, Karl offered his support by comforting Gloria and helping out behind the bar. He was still in love with Stella and wasn't happy with her new relationship with Jason Grimshaw. He tried to convince her that it wouldn't work because Jason was younger than her. After a meeting with the brewery, Karl picked her up and took her for a talk. He broke down and a sympathetic Stella comforted him; she said he should try and move on and stop seeing her. The next day, he returned only for Gloria to blurt out about Karl locking Stella in the taxi, which prompted Lloyd and Steve to sack him a second time; a smug Sunita looked on in glee. Karl later visited Sunita and threatened that he wasn't going anywhere. The next day, Karl stole Jason's van, torched it and gave Jason's description to the police. However Jason had an alibi (he was in the Rovers at the time). Stella, who didn't think Karl could be capable of doing such a thing, got him a job working for Owen Armstrong at the Builder's Yard.
2013 onwards: Rovers Fire, back with Stella and downfall
Karl's jealousy of Jason and Stella began to grow. On the evening of 18th March, as other Coronation Street residents were out partying at Nick's Bistro, Karl sneaked into the Rovers' cellar and, using alcohol as an accelerant; set fire to a piece of paper. Sunita, who had followed Karl down the ginnel, spotted him and asked for an explanation. She tried to escape from the cellar, but Karl grabbed her and pushed her down the stairs.
Sunita landed next to the emerging flames, unconscious. Karl was shocked to see his ex-girlfriend lying on the floor and quickly ran down the stairs. He discovered that Sunita wasn't moving. Panicked and thinking that he had killed her, he ran out of the pub, leaving her vulnerable to the fire.
Karl returned to the party just in time for the finale of the Full Monty. As Norris Cole and Emily Bishop came out of No.3 commenting on the noise coming from the Bistro, they spotted the Rovers was on fire and phoned the fire brigade. When Karl realised that Stella was inside the Rovers, he used the spare set of keys he'd stolen to rescue her. They made their way into the bedroom, where firefighter Toni Griffiths helped them escape, but Toni herself was killed in the blaze.
Convinced that she owed her life to Karl, Stella asked him to move in at 13 Coronation Street where the Price family were temporarily living, and although Jason didn't approve; he went along with the arrangement. Stella promptly dumped Jason and asked Karl to accompany her to Sunita's funeral. At the Crematorium, Karl broke down and admitted to Stella that he killed Sunita, although she didn't believe him and misread his confession. Stella and Karl shared a kiss before pulling back. Shortly after, this they rekindled their relationship.
Stella soon accepted Karl's proposal. Just prior to their wedding day, Karl admitted to Jason that he had torched his van, which led to Jason and Dev believing that Karl could have caused the Rovers' fire. Upon learning that Craig Tinker had seen him exiting the pub on the night of the fire, Karl convinced the lad that he was responsible and threatened to kill his mother should he ever open his mouth. Realising that something was terribly amiss, Beth, Dev and Kirk Sutherland coaxed the information out of Craig just after he had run away; Craig admitted to experimenting with smoking, but didn't like it and discarded a cigarette in the Rovers' yard. Explaining to him that the fire started in the cellar, they informed Craig that it was Karl who was the real killer. Jason took Craig to the police station to make a statement while Dev ensnared Karl in the pub. The pair began to fight and Dev was knocked unconscious. As Stella arrived at the pub and witnessed an injured Dev on the floor, Karl revealed all. The police arrived as Karl threatened to start a fire behind the Rovers bar. In his final moments as a free man, Karl held Stella in the pub's cellar but she managed to persuade him not to keep running and he was subsequently arrested.
Karl was later sentenced to a minimum of 25 years imprisonment. This means he won't be released until 2038.
- John Michie was introduced along with Michelle Collins as a new couple to take over the Rovers, along with Stella's on-screen daughter Eva played by Catherine Tyldesley. The actors filmed their first scenes in May 2011, which aired the following month.
- In April 2013, John Michie's contract was extended to see out the character's conclusion after recently setting fire to the Rovers and killing Sunita Alahan. He departed the series in September 2013, six months after the Rovers' fire.
First and last lines
"I got lost, alright? Everything looks the same around here. What? Had to say goodbye to the lads." (First line, to Stella Price)
"Come to see me off have you? Really touched." (Final line, to Jason Grimshaw before being arrested)