Aggravated voluntary manslaughter under cover of authority. Give him, say, 25 years, out in maybe 10 on good behavior; especially if he’s done well previously as a cop. OTOH, if he’s got a bad violence record and has been carried on the force, throw the book at him.
My take, FWIW.
I think you are more accurate.
Put him in the general population in a predominately black inmate prison.