How come indigenous peoples account for more than 20% of Canada's prison population?

It is true and the answers you will get will depend upon a persons viewpoint. Some will say that the laws and criminal justice system is slanted against the First Nations people and they are treated unfairly in that they are jailed more often when others are either fined, released, paroled or dealt with through other extra judicial means. Others will tell you that they commit more crimes and therefore end up in jail. Others still will tell you that society does not do enough to have them fit into society and their over representation in jail is an indication that society has let them down.