Brian Carroll (born 1953/1954) is the father of Dylan Keogh. At some point after Dylan's birth, he was put in foster care and estranged from his father.
In 2015, he was involved in a car crash with his girlfriend Hazel and they were admitted to the ED, where he was treated by his son. However, it transpired that Hazel was pregnant and he told Dylan that he didn't want him in his life anymore. (CAS: "The Long Haul")
By May 2016, Hazel had given birth to their baby daughter Rihanna. However, when Brian parked up his car and left the keys and Rihanna inside accidentally, he was forced to get a brick and smash his car window which resulted in him receiving a deep hand laceration. He was admitted to the ED and treated by Dylan, although neither were happy about it. Hazel arrived soon after and tried to convince Dylan that Brian had changed although he failed to believe her. Dylan later diagnosed Brian with a lung condition as a result of his smoking, and became angry with him when he caught him smoking outside the ED. (CAS: "Chain Reaction")
Hazel and Rihanna visited the ED in June as she was concerned for Rihanna's health. Brian later turned up and Dylan was furious at the possibility that Brian's smoking had caused it. (CAS: "History Repeating") Two weeks later following a fire at their house caused by one of Brian's cigarettes, he informed Dylan that he'd be leaving them. After this, Dylan offered to help out Hazel with Rihanna. (CAS: "Where the Truth Lies")
In July 2018, Brian stopped drinking. In October, Brian visited Dylan to make amends. Dylan dismissed him and decided to go to the pub, prompting Brian to offer him a lift and to bet that he could resist the urge to drink. At the pub, Dylan told him about his breakup with Ciara Cassidy and the loss of their child, and Brian apologised to him for his treatment of him and his mother. Dylan indulged him and told him that he could make it up to him by drinking with him. Brian refused and tried to leave, but, after Dylan criticised him for not having the guts to make a sacrifice for his son, he bit the bullet and started drinking. Once Brian became drunk, Dylan secretly went to the toilets and called Hazel. Shortly after, outside the pub, Brian got into an argument with her over the phone, and he was devastated when she broke up with him for good. He soon realised that Dylan called her and asked him if he wanted blood. Dylan told him that he wanted more than that, prompting Brian to goad him into "[being] a man" and hitting him. Dylan punched him in the face, causing Brian to hit his head on a nearby table. After Dylan briefly assessed him, Brian staggered up to him and collapsed in his arms. He carried him back inside, and he began to panic when Brian fell unconscious. David Hide, Zsa Zsa Harper-Jenkinson and Jeffers soon arrived, and Dylan begged Zsa Zsa to save his father. She reluctantly agreed and drilled a makeshift burr hole to evacuate a clot. When the clot was found, she persuaded Dylan to remove it. He managed to successfully extract it, and he accompanied Brian to the ED. (CAS: Series 33, Episode 9)
Behind the scenes
Matthew Marsh portrayed Brian Carroll for one episode of Casualty in 2015, "The Long Haul". He returned for three more appearances in series 30 in 2016. In August 2018, it was revealed that Marsh would reprise his role as Brian in autumn 2018.