I read Costanzo and Krauss's text Forensic and Legal Psychology: Psychological Science Applied to Law (2nd ed.) because I was considering using it as a text for a class.
I made a good choice. Forensic and Legal Psychology is readable, starts each chapter with great real-world case examples (e.g., Andrea Yates), and is strongly grounded in the science of psychology. It looks at sacred cows in the field and asks whether there is evidence supporting these and under what conditions. For those of you who aren't familiar with the psychological evidence for this field, there are many sacred cows that need to be slaughtered and allowed to fester in the long, hot sun.
I would never make a good juror.
I have resisted using an ebook for a text, even though I read on a kindle and like doing so for several reasons. I read Forensic and Legal Psychology on my iPad using the VitalSource app and, although I needed to fiddle with it a bit to get started, was pretty happy with its features and readability. (I still like the kindle app better, though.)