Despite extensive research on se*ual offending and personality pathology, critical gaps persist in understanding elite offenders who exploit wealth, intelligence, and social capital to evade sustained accountability. This dissertation addressed three converging problems: applying Dark Triad theory to real-world forensic cases, validating posthumous psychological assessment protocols, and examining how personality pathology interacts with affluence in systematic sexual exploitation. The purpose was to conduct comprehensive posthumous psychological assessment of Jeffrey Epstein (1953-2019) using the Dark Triad framework, comprising psychopathy, narcissism, and Machiavellianism. Utilizing qualitative case study design, this investigation systematically applied validated forensic instruments to an unprecedented archival corpus: 8,500+ pages of court documents, 2,300+ pages of victim testimonies, and extensive collateral materials spanning five decades. Two board-certified forensic psychologists independently conducted Psychopathy Checklist-Revised (PCL-R) assessments, DSM-5 diagnostic evaluations, and Machiavellianism behavioral analyses, with structured consensus resolution. The assessment yielded clinically significant findings: PCL-R total score of 29/40 (approaching clinical threshold), with maximum Factor 1 score of 16/16 (100%) reflecting profound interpersonal/affective deficits characteristic of successful psychopathy; severe Narcissistic Personality Disorder with 8 of 9 DSM-5 criteria met; and very high Machiavellianism across all behavioral indicators. Inter-rater reliability was excellent (κ=0.86, ICC=0.98), validating posthumous assessment protocols. Critical findings revealed synergistic Dark Triad interactions: psychopathic callousness enabled exploitation without remorse, narcissistic entitlement motivated and justified predation, and Machiavellian intelligence orchestrated sophisticated four-decade criminal enterprise. Superior cognitive functioning and extraordinary wealth dramatically amplified dangerousness through institutional manipulation and operational infrastructure. This investigation makes four significant contributions: validated methodology for posthumous Dark Triad assessment in forensic contexts; empirical demonstration of multiplicative trait interactions in high-functioning offenders; identification of cognitive ability and wealth as critical amplifying factors; and comprehensive mapping of institutional vulnerabilities exploited by personality-disordered offenders. Forensic implications include enhanced risk assessment protocols, refined understanding of successful psychopathy, evidence-based frameworks for civil litigation and victim compensation, and institutional safeguarding recommendations.