In the first series Dave is acting Head of the Review Team while the head is away on maternity leave, causing friction between him and Gill. In Series 1 he appears to be deeply jealous when Gill enters into a new relationship, which manifests itself in petty office sniping. During Series 2, in which his personal life collapses (to the delight of MIT), he barges into Gill's house and launches into a drunken speech that culminates in him tearfully asking her if she still has feelings for him; a visibly upset Gill nevertheless refuses to even consider giving him a second chance. Mary Jackson Mary Jackson (Julia Deakin in Series 2 and Judy Holt thereafter), or "Scary Mary" as she is nicknamed by the department, is one of the pathologists who carries out post-mortem examinations in the mortuary. Her morbid sense of humour plays well off Gill Murray's more blunt attitude, especially since Gill has a habit of personally attending crime scenes and port mortems. Dominic Bailey Dominic Bailey (Liam Boyle), Rachel's younger brother, is introduced in Series 2. He had previously served a prison sentence for armed robbery. With nowhere to go after Alison throws him out, he ends up living with Rachel, who encourages him to look for work. At one point she walks in on him selling sex to a man in her home; outraged, she tells him to get tested for HIV, which comes back negative. Dominic's stay with Rachel is marked by his irresponsibility and tendency to get in trouble; he nearly destroys her kitchen attempting to cook her a meal and crashes her car during a joyride, which forces her to miss her sergeant's exam. It is also suggested a few times that he had a drinking problem, and later on Alison and Rachel discuss the possibility that he is mentally slow. Despite her exasperation, Rachel continues to stand by him. In series 3 he is charged with murder and goes back to prison, though not before he alleges that Rachel provoked him to commit the crime, which leads to her brief (re)arrest. Sharon Bailey Sharon Bailey (Tracie Bennett), Rachel's mother, appears in the third series after being mentioned several times in Series 1 and 2. She is a boisterous, impulsive alcoholic who abandoned her children and is loathed by Alison, though Rachel tries to forgive her. Sean McCartney discovers that she was the