Something that should be considered by characters in a classic mystery story: it is never a particularly good idea to begin talking in a loud voice on the subject of "murderers I have known." It is an even worse idea to walk around with a picture of a murderer. Someone is likely to take offense, and that is liable to be injurious to your health.
That pretty well sums up what happens to an elderly retired British Army officer, Major Palgrave, who is staying on the Caribbean island of St. Honore. His story may be found in Agatha Christie's A Caribbean Mystery, originally published in 1964. A Caribbean Mystery is the subject of today's audio review on the Classic Mysteries podcast, and you can listen to the entire review by clicking here.
Major Palgrave is in the unfortunate habit of talking at great length about almost anything. His listeners, in fact, do not pay much attention. So even when he begins talking to Miss Jane Marple about a murderer whom he once saw and offers to show her a picture - then suddenly changes his mind and changes the subject - Miss Marple really doesn't listen to what he's saying.
Then Major Palgrave dies, quite suddenly. Apparently it was his high blood pressure; perhaps he wasn’t taking (or took too much of) that blood pressure medication found in his room. But it certainly wasn’t a surprise. Although nobody seems to be quite sure who it was who first began talking about the major’s high blood pressure...
Miss Marple, of course, becomes suspicious - with good reason. And she becomes worried that a murderer may be among the people at the resort on St. Honore - a murderer who may be making plans to find a new victim.
A Caribbean Mystery is one of the really good Miss Marple novels. There are a lot of very interesting characters, of course, and the plot is one of Christie's nicest uses of misdirection. The clues are there if the reader can spot them. I recommend it highly.