In a recent conversation with some other authors, the topic of prologues came up. The comments about them were all over the map. Some people in the discussion thought prologues could be beneficial as long as they were no more than a page or two.
Others felt that prologues are okay if the info in them is useful to the reader but will not be revealed until the end of the book (or nearly the end of it).
A few people pointed out that prologues can come in handy if the story is told in the first person and that it's inconceivable for the protagonist to come across the info.
Overall, though, the general consensus was that prologues should be avoided, and I'm now leaning that way...
For The Lies Have It, the 3rd Sasha mystery, I originally did have a prologue, but it was chopped before going to the printer. I am glad in the end that I got rid of it, but it took some convincing from my editor.
I'm presently working on book 4, and until recently, it also had a prologue, but it has now been axed. In the case of my current work in progress (which will be called Frisky Business), I think the prologue gave an indication of why someone might be prompted to act, or do, or say something that ultimately turns the book into a murder investigation for PI Sasha Jackson. But the prologue felt clunky. So, I'll just have to figure out another way to get that information across... and after many hours of thinking about it, I think I've figured it out. I hope!