Regarding the prevalence of such homicides in the United States during this period, those resulting from an attack on a law enforcement officer increased by 67 percent, from an average of 153 to 255 per year. Although no relevant national data are collected, multiple informal studies and accounts support the conclusion that at least half of the people shot and killed by police each year had mental health problems. There are indications that many of the mentally ill individuals under treatment for mental illness were not taking their medications. Some were also well-known to law enforcement officers from previous encounters. Studies also suggest that approximately one-third of the shootings resulted from attackers precipitating the encounter as a means of suicide ("suicide-by-cop"). In addition, relevant studies conclude that the prevalence of law enforcement officer encounters with mentally ill attackers stems from the failure of the mental health system to manage such high-risk patients in an appropriate manner. Recommendations based on these findings pertain to nationwide data collection on this issue; the accountability of the mental health system; and the enactment and enforcement of State laws mandating court-ordered assisted outpatient treatment as a condition for remaining in the community for mentally ill patients who meet specified criteria. Data are provided for 44 such homicides.