This study identified factors that predicted which of 713 clinically documented incidents of aggression—threats to kill, assault, or sexual assault—committed by 404 forensic psychiatric patients were linked to court findings of guilt. Individuals had, on average, 1.7 aggressive incidents and were found guilty of an average of 0.3 offenses against persons during the study period. Aggressive incidents were mostly assaults, followed by uttering death threats, and sexual assaults. The victims of aggressive incidents were mainly other patients or staff, but some incidents involved family members or friends (16%) and strangers (14%). Most of the aggressive incidents (84%) did not lead to findings of guilt. Incidents of aggression linked to court findings were significantly associated with province; personality disorder; fewer prior aggressive incidents; and incidents involving strangers compared to staff or co-patients or to family or friends. These findings have implications for research in terms of understanding how criminal records underestimate histories of aggression. These findings also point to the need for the development of more consistent policies and procedures for responding to patient aggression, including when it is necessary or productive to report to police.