Police Homicides in the United States

As a counterpoint to the headline that might be little fear-inducing, my first reaction when reading it was: only so little? Things must be bad.

I mean: the perfect situation is when there are no homicides at all. But in a little less perfect imaginary world, in which bad people never get the chance to hurt innocents because police stops it, some bad people might still go down resisting arrest, at which point 100% of all homicides would be police-inflicted, and that would be good. Not perfect, but better than what we have.

Statistics are funny this way.

The real question is, how many of those killed by the police were killed in totally justifiable self-defense, and not just because of policemen being trigger-happy. Or, put another way, what's the probability that a person who is not resisting arrest to get "accidentally" killed by the police.

e.g. Imagine a world where police do their job even better, and eliminate all murder. But, in some cases, they have to kill the murderer before he takes an innocent victim. They never kill unless it's absolutely necessary and justified. In such a world, this statistic rises to "All people killed by strangers are killed by police", which sounds worse than the headline, yet such a world is obviously better than ours.

e.g. Imagine a world where police never do anything. They drink beer in the station all day. All people killed by strangers are killed by non-police. Such a world is much worse than ours, yet this stat looks a lot better.

Just these very simple thought experiments should give you pause about what this statistical comparison actually means (or if it means anything at all).

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My two questions to those who think this is some sort of obvious travesty:

1. What would be a healthy ratio between [people killed by non-police strangers] and [people killed by police]? 1:5? 1:10? 1:100? Why?

2. How is this random choice of two statistics not just another variation on the Chinese robber fallacy? [1]

[1] http://slatestarcodex.com/2015/09/16/cardiologists-and-chine...

Germany: 2155 homicides in 2011, 6 by the police.

If your issue is with the "final" 1,500 number (increased from 1,250), you'll find that it's well-supported in both the blog post:

>>> Keep in mind that the Bureau of Justice Statistics report itself excludes many jurisdictions in the United States that openly refuse to share any data with the FBI. The true number of homicides committed by police is therefore even higher. Though not a true estimate, my best guess of the number of police homicides in the United States is about 1,500 per year.

And the paper:

>>> As mentioned in Banks et al. (2015), these list intersection counts only include jurisdictions that reported any data (about 70%). As such, these numbers should be interpreted as estimates of the number of people killed by police in the reporting jurisdictions. If the reporting jurisdictions are missing from the dataset not because there were truly no killings in those areas during this period, but instead because they chose not to report homicides by police, the true number of police homicides could be 30% higher than we have suggested here.

Note that 1500 represents a 20% increase over 1250, which is lower than the 30% maximum estimate presented in the paper.