I wanted to calculate this relative risk for a talk. I started by trying to find out how many people are killed by police in each country.
For the US in 2015, I found four sources that gave varying counts. The Washington Post reported that 990 people were killed by police gunshot. The Guardian counted 1,110 killed. The Gun Violence Archive counted 1,049. KilledByPolice.net reported 1,207. The average of these counts is 1,089.
The estimated US population on July 4, 2015 was 321,442,019. So
Risk in America = 1,089 / 321,442,019 = 3.4 / 1,000,000.
This is a small absolute risk. There were 42,773 suicides in the US in 2014, or 134 / 1,000,000, so an American is about 40 times more likely to take his own life than he is to lose it by being shot by the police.
For Canada, Wikipedia has a list of people killed by police since 1932. There were 20 killed by gunshot in 2015. The Canadian population on July 1, 2015* was 35,851,800. So,
Risk in Canada = 20 / 35,851,800 = 0.56 / 1,000,000.
We can compare these numbers by calculating the relative risk of dying by police gunshot in the two countries:
Relative risk = Risk in America / Risk in Canada = 6.1.
This is a large relative risk, larger than the risk of getting cancer if you are a woman with the BRCA1 gene relative to the risk if you are a woman in the general population. Keep in mind, this large relative risk doesn’t mean that the absolute risk of getting killed by the police in America is large. As we have seen, it is small. Moreover, the number tells us nothing about what causes the higher rates of death by police gunshot in America. But I think we can agree that there are more deaths by police gunshot in America than there should be.
If we are going to improve this situation, one place to start is measuring the problem. But as you have seen, that’s not going well. You would think that shootings by police in the US would be sufficiently important that we would count them accurately. FBI Director Comey thinks so too:
“You can get online and figure out how many tickets were sold to The Martian,” said FBI Director James Comey in October, expressing his frustration. “It’s ridiculous — embarrassing and ridiculous — that we can’t talk about crime in the same way, especially in the high-stakes incidents when your officers have to use force.”
*Canada Day, if you did not know.