It seems to me that the prologue is very prevalent in thrillers these days.  Often you get a different point of view.  You get a look into the mind of the (serial) killer.  Or you know who did it.
How does that work for you for a mystery?  Do you as a reader like to only know what the detective knows, so that you can solve things or be surprised along with the detective?  Or do you like knowing something the detective doesn't know, so you can see the train wreck coming, so you can squirm, so you can root for the detective to avoid disaster?