Police use of lethal force occurs rarely and is legally permissible when used appropriately. When police use fatal force, their behavior is highly scrutinized by the legal system and the public. The present study analyzed factors characteristic of 45 coronial investigations of police engagements that culminated in civilian fatalities between 1980 and 2008 in Victoria, Australia. Findings suggest that fatalities commonly occurred at arrest during unplanned police operation, and the majority of incidents were of short duration. The majority of the decedents were armed, acted aggressively, resisted arrest, and escalated the incident. A third of the incidents met the criteria for possible suicide by police. Differences in mental health, incident, and police response characteristics were found between those who met these criteria and those who did not. The findings and their implications for law enforcement, the public, and the mental health system are presented and discussed. Abstract published by arrangement with Sage Journals.