This paper is a descriptive review of the phenomenon of paraphilias, the relationship of possessing multiple paraphilias with the commission of sexual crimes and serial murder and the recognition of evidence related to sexual crimes committed by offenders with paraphilias. Several case studies are presented and the manifestations of multiple paraphilias, such as those experienced by Jeffrey Dahmer, Albert Fish, and others, are conceptualized and divided into three types: (i) replacement--no overlap; (ii) replacement with overlap; and (iii) cumulative. The categories are further divided into primary, secondary, and collateral paraphilias. Primary and secondary paraphilias are mutually exclusive and one does not build upon the other. Collateral paraphilias may serve to enhance the overall sexual experience of the primary and secondary paraphilias, including the sexualization of props or weapons. Implications for criminalists and criminal investigators are explained, particularly the value in discerning hidden as well as salient evidence of paraphilic behaviors left at crime scenes.