We absolutely have this in the UK. The IOPC are the body who people can complain to about police conduct and would investigate. I presume most normal countries

We absolutely have this in the UK. The IOPC are the body who people can complain to about police conduct and would investigate. I presume most normal countries have such a thing. I believe any death is automatically referred for review, even if there is no evidence of wrong doing, as it’s so unusual.