Concerning the discussion about the connection of personality traits, personality disorders, and mental illness, this study focused on the personality profiles of male forensic patients, prison inmates, and young men without criminal reports. The main topic centered on group-specific personality profiles and identifying personality facets corresponding with mental illness. The authors therefore used the Rasch model-based Trier Integrated Personality Inventory. They individually tested 141 German forensic patients with different crime backgrounds, 122 prison inmates, and 111 soldiers of the German army. Within group differences they found that the individuals with mental retardation differ from patients with a personality disorder or psychosis. Patients with mental retardation displayed higher neurotic and/or paranoid personality accents and tended to be low organized and self-confident. (Contains 5 figures and 3 tables.)