Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good investigator, not such a good writer

Keppel is obviously a very intelligent man with vast experience in serial murder investigation, and at the forefront of his field. The book explores some very interesting concepts through the use of many famous investigations. However, Keppel seems to write with a real lack of emotion, which I guess is necessary in his job. Which is why he should stick with that job instead of trying to be a writer. The lack of emotion made it feel like I was reading a calculus textbook. Keppel also seems to repeat himself over and over throughout the different chapters. This only adds to the boredom.