The analysis of personality tests concluded that the offender had indicators of a schizoid personality organization (asocial, introverted, affectively insensitive) without signs of psychotic decompensation. The most prominent characteristics of this personality disorder are at an interpersonal level and include social withdrawal, social isolation, and avoidance of intimacy. A spectrum of negative emotions toward others is expected (e.g., hostility, anger, and vindictiveness). Social alienation creates a sense of rejection that can precipitate violence. The offender's description of the crime is an example of dissociation during the commission of the offense. His description of the killings shows the presence of an "out of body experience," as he viewed himself as a shadow and watched his parents as they were struck. At no time did he use first person or speak of himself as the offender/precipitator of the event. This "detachment" experience is an essential part of the definition of depersonalization according to DSM-IV. Another goal of this study was to demonstrate the applicability and usefulness of non-standard testing and theory-driven psychological instruments, such as the Behavioral Inhibition System and Behavioral Activation System (BIS/BAS) Questionnaire. This instrument is derived from Jeffrey Gray's reinforcement sensitivity theory, which originally assumed three basic emotional systems: Behavioral Inhibition System (BIS), which is sensitive to conditional aversive stimuli; Behavioral Activation System (BAS), which is sensitive to conditional appetitive stimuli; and the Flight/Fight System, which is sensitive to unconditional aversive stimuli. 1 figure and 27 references