[rahimnathwani]

"Wait a second, why is the chance of getting shot and killed by the police a per capita statistic."

To normalize data collected from jurisdictions with different populations.

"The denominator should be the number of police-initiated encounters."

It depends what you care about. If you're a black man in America, perhaps you care about the overall chance of dying this way.

Perhaps, conditional on having been stopped by police, the chance of being shot and killed is the same for white men and black men. But this would be irrelevant if black men are 10X more likely to be stopped in the first place.