Pretty bad writing -- there were incomplete sentences (suject + predicate = sentence...did we not learn this in third grade?!), spelling errors, grammatical errors, and some badly placed slang that is totally inappropriate for journalistic writing.
Other than the terrible writing, the book itself is an excellent reference, and seems fairly well-researched. I read it from cover to cover, although I would recommend just using it as a reference instead. Some of the accounts are pretty dry.
Still, for those fascinated by female criminals or crime in general, it's a decent read.