Two important developments are addressed by this dissertation. First, the Psychological Inventory of Criminal Thinking Styles-Simplified Version (PICTS-SV) was examined in relation to the original PICTS. Second, the vulnerability of the PICTS-SV to intentional risk minimization (RM) was tested. Two separate studies recruited a total of 150 offenders from a court-mandated residential substance use treatment facility. As expected, Study I established the PICTS-SV's good concurrent validity with the PICTS, especially at the broad composite scale level. For Study II, criminal thinking failed to show the anticipated convergence with HCR-20 risk classifications or forensic correlates. Potential explanations, including a restricted range of risk levels in this sample, are discussed. As a particular strength, the findings highlight that the PICTS-SV, in contrast to many risk measures, displays robust resistance to RM distortion, although revisions to its Df-r validity scale are warranted. These results overall demonstrate strong evidence of the PICTS-SV's utility for assessing a dynamic criminogenic need to inform effective interventions and accurate risk determinations.