For what it’s worth, the homicide rate in the United States has been falling for the past 25 years. Specifically the number of killings of police officers has been falling, too.
Evidently there was an increase in the murder rate in certain American cities last year and early this year, but it’s too early to tell if this will reverse the long-range trend.
There is a long-term decline in killings of police officers.
I’m not sure of the trend in the killing of African-Americans by police.
The first chart below is from the Centers for Disease Control, which includes a long-term decline in police killings of African-Americans. The next is from FBI Uniform Crime Reports and gives a different impression because it is based on a 20-year time period instead of a 50-year time period; I include it because it is more up to date.
Both are based on admittedly incomplete reporting systems. Neither provides information as to how many of the killings were justified in order to protect human life.
FBI: Homicide Rate at 51-Year Low by Ryan McMaken for the Mises Institute.
Is there really a ‘war on cops’? by Mark J. Perry for the American Enterprise Institute.
FBI Confirms 2015 Was One of the Safest Years Ever for Cops by Matt Ferner for Huffington Post.
What Caused Crime to Decline in the U.S.? by Matt Ford for The Atlantic.
‘Ferguson Effect’ is a plausible reason for the spike in U.S. violent crime, study says by Jamiles Larty, Ryan Felton and Lois Beckett for The Guardian.
Are deaths from police shootings the highest in 20 years? by Steve Contorno for PolitiFact.