Although data are inconclusive, popular perception has linked military combat, posttraumatic stress disorder (PTSD), and criminal behavior. This paper discusses the multifactorial elements of this association that include both conscious and unconscious parameters of psychologic functioning. Testimony on combat-related PTSD has been presented in the courtroom to support veterans' claims of not guilty by reason of insanity (NGRI) and diminished capacity and for consideration during judicial sentencing. Because there is a known connection between the degree of combat involvement and PTSD, verification through collateral sources of the veteran's report of combat experiences is an important component of forensic assessment. The DSM-III-defined diagnosis of PTSD and the presence of a dissociative state have particular relevance in NGRI determinations. In other aspects of the judicial process demonstration of the absolute presence or absence of PTSD is often irrelevant and should be replaced by efforts to establish plausible links between provable combat experiences and the circumstances of the crime.