This was posted to a list I belong to and now I'm on a quest to see if I can find out about these books as well.  Anyone have any ideas as to what these books may be?

"[I have been] reminded... to finally ask you about a series of
children's books. I've scoured Mystery bookshops and can't find a
lead. When I was young, my oldest brother procured these 'murder
mystery' game books and of course we had to play them discretely so as
not to be discovered by my very pious mother. These gamebooks were
oversized and had really graphic, grisly illustrated crime scenes and
a list of clues and short story to go along - you had to follow the
clues and find more in the pictures to figure out the mystery.
Thinking back, these were quite inappropriate for children and of
course, I'm dying to get my hands on them now!! Do you have ANY idea
what they were called???"