That stat alone doesn't tell us if the disparity is due to different rates if criminal behavior, or different treatment by the system. A useful check is to look at murder victimization rates, since a) murder is almost always reported, and b) most murders are intra-racial.

The doc you linked says 39% of inmates are First Nations, and this[0] says they are 37% of Alberta murder victims.

Of course this isn't saying that there isn't inequality in the system, but just that happens before someone gets sentenced.

[0] https://www150.statcan.gc.ca/t1/tbl1/en/tv.action?pid=351001...

We could further ask why racialized minorities might have higher crime rates, such as how those people have been treated by society and the state.

But that’s unrelated to the “racism” comment above. European Canadians came and destroyed the indigenous Canadian population, scattered their population and upended their societies. But Canadians today might treat indigenous people without any prejudice.

Generally speaking, crime isn’t a matter of economics. My dad’s village in Bangladesh in the 1950s—when 1/4 of kids died before the age of five—was safer then than Toronto is today.

Worth keeping in mind that even a lot of these cases weren't treated as murder...

Why else would different races have different rates of criminal behavior?

Historical socioeconomic factors, things that aren't fixed within a handful of generations

Also culture, socialization, and community structure (which may also be the result of historical events).

“Socioeconomic factors” by themselves have limited explanatory potential. Even the poorest Canadian reservations are wealthier per capita than India is now or China was a few years ago. But the homicide rate among indigenous Canadians is about double what India’s was in 1990, and triple of what India’s is today. It’s almost 20 times higher than China’s homicide rate.

Genes.

For all sorts of reasons?

British Pakistanis and British Hindus look basically the same, especially to a naive native European, but the groups are internally different enough to be on the opposite ends of the British societal ladder in all sorts of attributes - education, wealth, crime rate etc.

This is a complicated issue that I don't see being solved in my lifetime. The higher-than-average crime of this population is genuine and not solely attributed to false racial persecution. Surely some of it is, but it would not account for the entire skew. All it takes to see this is to take a ride on the Edmonton transit system or spend a week in Maskwacis. Obviously the crime is a result of poverty, generational trauma, historic mistreatment and cultural genocide, and IMO the failure of the reserve system. How do you fix it, I don't know... but acknowledging treaty land at every public event and re-naming streets in Cree is probably less useful than fixing the third-world conditions of reserves.