Darkside by Belinda Bauer

Jonas Holly is the local policeman in the area of Exmoor, which covers his home village of Shipcott. When paralyzed neighbor Margaret Priddy is found murdered in her bed, DCI Marvel and his colleagues are called in. Marvel is abrasive and verbally abusive to Jonas for his handling of the crime scene. Despite this fact, Jonas has to work alongside Marvel's team. When another local resident is killed, the authorities wonder if someone is killing people to put them out of their misery, since the second victim suffered from dementia. On the home front, Jonas is watching his wife, Lucy, lose more of her strength because of having multiple sclerosis and is rattled by anonymous notes he's receiving about him not doing his job properly. He fears they are from the killer. In Darkside, Bauer has written a police procedural which is similar to the author Tana French and the Simon Serrailler series by Susan Hill. Darkside is also set four years later in the same town as her first novel, Blacklands. It will be published in May.