Read while camping the first in Margery Allingham's Albert Campion novels, The Black Dudley Murder, which in the UK was published as The Crime at the Black Dudley. The UK title is actually more interesting once one finishes the novel because
There is a criminal gang, who are definitely up to no good, and at least one member of the gang commits medical fraud; and during the course of the book, the gang commits various acts of nastiness like taking people hostage, assault, etc. So I guess they do commit crimes, but not the big CRIME one comes to a murder novel for.
Because it becomes clear that none of the gang actually committed the murder about 2/3rds of the way through. And so then the reader (and the protagonist and the "society" toffs) have to face the fact that one of them committed the murder. But the man murdered was himself a criminal, who had created some semi-mind control/psychological manipulation of young women turning them into "fallen women". So, was that actually a crime to kill him (was what I believe the author was interrogating at the end)?
Thus the UK title is quite subtle, and interesting. Whereas the American title is, as Americans are wont to be, a straight shooter (ahem).
Interesting thing about this one, it was not told from Albert Campion's POV, but someone else. I enjoyed his character though, everyone thinks him a fool at first, but he uses that to his advantage multiple times; and eventually the more perceptive of the various characters realize he's got a lot more going on upstairs than he appears. I've got another 3-4 of the Campion books on my shelf, so glad the book wasn't a total turnoff.
Also fun easter egg, I recently read (and just this past Wednesday posted) the first mystery novel by Allingham, The White Cottage. And while the Campion novels start with Black Dudley, the previous novel is connected in that the Scotland Yard detective referred to in both novels is Inspector Deadwood. So entertainingly, these are actually part of the same "Allingham-verse", albeit only Black Dudley is a "Campion" novel.