I must admit that, if I saw this book in a shop, I wouldn't buy it. It looks like a children's book or one of those supermarket "Bumper Guide to" titles.
I was wrong, though. This is a great book. It is laid out by technique (Ballistics, DNA, Odonotology etc) then chronologically by case so you can see the development of the method over time.
The cases are quite short (ranging from one page to three or four) but a lot of information is imparted. Usually, we hear about the crime, the trial and the conclusion. The descriptions are straight forward and, while sometimes shocking, they are not needlessly gruesome.
It is a book pitched to anyone with an interest in forensics - the legal and medical professions as well as the general reader. This would probably be a great starting point for anyone doing background research but probably doesn't go into enough detail to be particularly useful on its own.
Don't be put off by the cover (or the title for that matter!), this is a great read.