In the music world a country and western song that becomes a rock favorite is called a crossover. The same sort of phenomenon is happening in the book world these days between the murder mystery and the "serious" novel genres.
I've read two mysteries in the last month that can hold their own as novels needing no mystery modifier before a reviewer can praise them. There have been more and more of these in recent years.
Meanwhile the novel - no modifier - has divided into two distinct sub-genres, unreadable and unrealistic trash and unreadable and disturbing "literary fiction." The middle ground of well-plotted, deftly written novels with at least marginally admirable characters who come alive on the page - books you enjoy reading and from which you learn something - is thinning.
Yesterday I finished a novel by Canadian author Louise Penny called Still Life (2005.) It's a story with a murder and a detective and a controlled group of suspects. It's also a story with characters whose view of the world and reaction to it are complex and understandable. There is some artificiality of course. The reader must be made to consider each major character as the possible killer and so a layer of distrust is laid over each in turn.
I mention Penny's nationality because this is a book about Canadians. You would not mistake any of these folks as British or Americans. They live in a Loyalist town, one of those villages just across the border from the US to which, during the American Revolution, Loyalists to the British Crown fled and settled. It may be this well-remembered history that gives the people their pronounced definition.
I recommend this novel to readers of popular page-turners, to mystery fans, and to the "serious" reader who is looking for "serious" fiction. It has it all.