"Charles Todd" is the pen name used by a mother-son writing team. They write two historical mystery series. The Inspector Ian Rutledge series has 16 books so far.
A disclaimer - I have yet to "read" an Inspector Ian Rutledge book. I have listened to a handful. I don't know what it is about Simon Prebble as a narrator, but he has one of the best voices I've heard for keeping me awake and engaged while driving long distances. He is right up there with Rob Inglis (narrator of The Hobbit and The Lord of the Rings) and Jim Dale (narrator of the American editions of The Harry Potter series). When I listen to Simon Prebble I just want the story to keep going. I listened to Hunting Shadows over about a month.
Inspector Rutledge is an interesting character, a Great War veteran with PTSD and a guilt-induced imaginary companion who haunts him. Rutledge is particularly careless in Hunting Shadows, allowing himself to be vulnerable in front of murder suspects, but since he sometimes thinks about killing himself to be rid of the guilt that's not *that* hard to accept. It's nice that he is a flawed character. I do think he could benefit from a regular companion (one that is alive, that is). I'd love to see more of his sister in the books.
The mystery is fine, the plot is fine. This isn't great literature but highly enjoyable historical fiction. And Simon Prebble is awesome! I'd listen to him read anything.
I recommend both series by Charles Todd. The Bess Crawford series is about a Great War nurse. The Galesburg Public Library has both series in multiple formats, and a number of audiobooks narrated by Simon Prebble.