This book has been published at a time when there is a great interest in and awareness of sex offenders—in particular, their assessment, treatment, and rehabilitation. It is imperative to note that sex offenders, despite their common behavioral denominator, do not constitute a homogeneous population. To the contrary, sex offenders are quite heterogeneous, particularly with respect to phenomenologic, clinical, and, where known, etiological characteristics. Although many sex offenders may be motivated by criminal intent, it is important to point out that some of the individuals who engage in illegal sexual activities may be more prone to do so because of an underlying psychiatric disorder. In fact, a subpopulation of sex offenders may have a paraphilia or sexual deviation syndrome. Yet others may be psychotic or manic or may have cognitive proclivities that render them more vulnerable to committing criminal acts, including sexual violence. Although Salter addresses issues related to psychopathy and antisociality and differentiates "child molesters" from "rapists" and "sadists," she unfortunately does not offer, notwithstanding her considerable expertise, an in-depth analysis of the differential diagnosis of sexually offending behavior. Omitting such a discussion substantially undermines efforts to explicate behaviors that may constitute a sex offense.