While history turns on pivotal events, the wheels of justice grind slow. So we find in “The Cadaver King and the Country Dentist” by Radley Balko (“Rise of the Warrior Cop”).  Drs Steven Hayne and Michael West built successful careers as medical examiners in rural Mississippi, performing autopsies and serving as go-to experts for prosecutors.  But the evidence they provided was often faulty and biased, notably so in the cases Kennedy Brewer and Levon Brooks, both wrongly convicted  on the basis of the examiner’s evidence; both were acquitted in 2007. The authors methodically dissect the doctors’ testimonies and the justice system in which they were allowed to flourish.